3base (Newbee)
06-04-02 18:49
No 317544
      benzaldehydes via cleavage of styrenes  Bookmark   

this thread is dedicated to the preparation of benzaldehydes
via the cleavage of styrene derivatives.

depending on the cleavage reaction, the corresponding benzoic
acids are often byproducts or in several cases even main products.

see Post 317536 (3base: "benzaldehydes from benzoic acids", Chemistry Discourse) for suggestions how to convert benzoic acid
derivatives to the corresponding benzaldehydes.
 
 
 
 
    3base
(Newbee)
06-04-02 18:51
No 317545
      piperonal from isosafrole
(Rated as: excellent)
 Bookmark   

isosafrole --> piperonal
ozone, yield 96%
tetrahedron letters, 1966 36, 4273-4278; pappas et al
chemical abstracts 1966 65, 16890g


isosafrole --> piperonal
oxidation, K2Cr2O7 and H2S04, yield 47%
j chem ind tokyo, 1920 23, 56-79; nagai
chemical abstracts, 1920 14, 2839

isosafrole --> piperonylic acid
potassium permanganate
byproduct: piperonal(yield 8%)
j chem ind tokyo, 1920 23, 56-79; nagai
chemical abstracts, 1920 14, 2839

isosafrole --> piperonal
J Chm Ind Toky 23, 56+151+342 (1920)


isosafrole --> piperonal
Chem. Trade J. and Chem. Engr. 359 (1926)
 
 
 
 
    3base
(Newbee)
06-04-02 18:57
No 317548
      vanillin from 3-methoxy-4-hydroxy-propenylbenzene
(Rated as: excellent)
 Bookmark   

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
H2O2, tert-butyl alcohol / tert-pentyl alcohol, CrO3 / V2O5
Patent US2437648; 1943; research corp
Patent US2402566; 1942; research corp
Patent US2414385; 1942; research corp
j amer chem soc, 1937 59, 2342; milas

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
aqueous H2O2, sulfanilic acid, peroxidase-substance
biokhimiya (moscow), 1942 7, 109 111; manskaja, emeljanowa
chem abstr, 1943, 4525

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
ozone
j soc chem ind london, 1922 41, 70 R.; anonymus
helv chim acta, 1925 8, 407; briner, v tscharner, paillard
helv chim acta, 1924 7, 71; briner, patry, de luserna

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
aqueous alkali, elektrolytische oxydation an Pt-, Fe- oder PbO2-anoden
trans am elektroch soc, 42, 276 280; lowy, moore
chem zentralbl, 1923 94 III, 1516; lowy, moore

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
aqueous alkali, 0-12C, elektrolytische oxydation an PbO2-anoden
helv chim acta, 1925 8, 333; fichter, christen

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
oxygen, glacial acetic acid
chem ber, 1915 48, 40; harries, haarmann

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
air, acetic acid, 50-60C, irradiation mit ultraviolettem licht
Patent DE224071; genthe & co
fortschr teerfarbenfabr verw industriezweige, 9, 1130; genthe & co

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
ozone, glacial acetic acid
ann chim (paris), 1898 <7>13, 123; otto
chem ber, 1915 48, 232; witt
chem ber, 1915 48, 40; harries, haarmann
Patent DE97620; otto, verley
fortschr teerfarbenfabr verw industriezweige, 4, 1280; otto, verley

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
ozone, acetic acid ester
man reduziert das entstandene ozonid in aether mit zink und eisessig
chem ber, 1915 48, 40; harries, haarmann

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
air, durch ueberleiten des dampfes ueber eine gluehende platinspirale
c r hebd seances acad sci, 1901 133, 822; trillat
bull soc chim fr, 1903 <3>29, 41; trillat

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
alkali chlorate, osmium tetroxide
Patent DE267906; hofmann
chem ber, 1912 45, 3336; hofmann
chem zentralbl, 1914 85 I, 199; hofmann

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
oxidation, yield 58%, rhodococcus rhodochrous MTCC 289, 3 days, 30C, pH6
indian j chem sect b, 1999 38 5, 538-541; t chatterjee, b k de, d k bhattacharyya

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
air, terpentine oil
Patent DE150981; froger-delapierre

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
ozone, sodium disulfite
Patent DE192565; spurge

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
alkali, electrolysis
patent, Patent DE92007; chem fabr v heyden
fortschr teerfarbenfabr verw industriezweige, 4, 1279; chem fabr v heyden

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
peroxidene, alkali
Patent DE93938; haarmann & reimer
fortschr teerfarbenfabr verw industriezweige, 4, 1277; haarmann & reimer

3-methoxy-4-hydroxy-propenylbenzene --> vanillin
manganese saltene
Patent DE189178; lang
 
 
 
 
    3base
(Newbee)
06-04-02 20:05
No 317565
      isoeugenole --> vanillin
(Rated as: excellent)
 Bookmark   

isoeugenole --> vanillin

Reaction Details 1 of 22; 2 of 22 ; 3 of 22 ; 22 of 22
Reaction Classification Preparation
Reagent H2O2
 tert-butyl alcohol or tert-pentyl alcohol
Other Conditions Reagens 4: CrO3 or V2O5
Note 1 Handbook
Ref. 1 1363245; Patent; Research Corp.; Patent US2437648; 1943.
Ref. 2 1587093; Patent; Research Corp.; Patent US2402566; 1942.
Ref. 3 1587094; Patent; Research Corp.; Patent US2414385; 1942.
Ref. 4 519401; Journal; Milas; JACSAT; J.Amer.Chem.Soc.; 59; 1937; 2342.

Reaction Details 4 of 22
Reaction Classification Preparation
Reagent aqueous H2O2
 sulfanilic acid
 peroxidase-substance
Note 1 Handbook
Ref. 1 1987161; Journal; Manskaja; Emeljanowa; BIOHAO; Biokhimiya (Moscow); 7; 1942;

109,111; Chem.Abstr.; 1943; 4525.

Reaction Details 5 of 22
Reaction Classification Preparation
Reagent ozone
Note 1 Handbook
Ref. 1 1545909; Journal; Anonymus; JSCIAN; J.Soc.Chem.Ind.London; 41; 1922; 70 R.
Ref. 2 507359; Journal; Briner; v. Tscharner; Paillard; HCACAV; Helv.Chim.Acta; 8; 1925;

407.
Ref. 3 1545911; Journal; Briner; Patry; de Luserna; HCACAV; Helv.Chim.Acta; 7; 1924; 71.

Reaction Details 6 of 22
Reaction Classification Preparation
Reagent aqueous alkali
Other Conditions elektrolytische Oxydation an Platin-Anoden
Note 1 Handbook
Ref. 1 1982322; Journal; Lowy; Moore; Trans.am.elektroch.Soc.; 42; 276,280; CHZEA6;

Chem.Zentralbl.; GE; 94; III; 1923; 1516.

Reaction Details 7 of 22
Reaction Classification Preparation
Reagent aqueous alkali
Temperature 0 - 12 C
Other Conditions elektrolytische Oxydation an Bleidioxyd-Anoden
Note 1 Handbook
Ref. 1 1541589; Journal; Fichter; Christen; HCACAV; Helv.Chim.Acta; 8; 1925; 333.

Reaction Details 8 of 22
Reaction Classification Preparation
Reagent oxygen
 glacial acetic acid
Note 1 Handbook
Ref. 1 1533646; Journal; Harries; Haarmann; CHBEAM; Chem.Ber.; 48; 1915; 40.

Reaction Details 9 of 22
Reaction Classification Preparation
Reagent air
 acetic acid
Temperature 50 - 60 C
Other Conditions Irradiation.mit ultraviolettem Licht
Note 1 Handbook
Ref. 1 1533596; Genthe & Co.; Patent DE224071; FTFVA6;

Fortschr.Teerfarbenfabr.Verw.Industriezweige; DE; GE; 9; 1130.

Reaction Details 10 of 22
Reaction Classification Preparation
Reagent ozone
 glacial acetic acid
Note 1 Handbook
Ref. 1 500446; Journal; Otto; ANCPAC; Ann.Chim.(Paris); <7> 13; 1898; 123.
Ref. 2 1533598; Journal; Witt; CHBEAM; Chem.Ber.; 48; 1915; 232.
Ref. 3 1533646; Journal; Harries; Haarmann; CHBEAM; Chem.Ber.; 48; 1915; 40.
Ref. 4 1523833; Otto; Verley; DE97620; FTFVA6; Fortschr.Teerfarbenfabr.Verw.Industriezweige;

DE; GE; 4; 1280.

Reaction Details 11 of 22
Reaction Classification Preparation
Reagent ozone
 acetic acid ester
Other Conditions man reduziert das entstandene Ozonid in Aether mit Zink und Eisessig
Note 1 Handbook
Ref. 1 1533646; Journal; Harries; Haarmann; CHBEAM; Chem.Ber.; 48; 1915; 40.

Reaction Details 12 of 22
Reaction Classification Preparation
Reagent air
Other Conditions durch Ueberleiten des Dampfes ueber eine gluehende Platinspirale
Note 1 Handbook
Ref. 1 1296879; Journal; Trillat; COREAF; C.R.Hebd.Seances Acad.Sci.; 133; 1901; 822;

BSCFAS; Bull.Soc.Chim.Fr.; <3>29; 1903; 41.

Reaction Details 13 of 22
Reaction Classification Preparation
Reagent alkali chlorate
 osmium tetroxide
Note 1 Handbook
Ref. 1 1977927; Hofmann; Patent DE267906.
Ref. 2 1977928; Journal; Hofmann; CHBEAM; Chem.Ber.; 45; 1912; 3336; CHZEA6;

Chem.Zentralbl.; GE; 85; I; 1914; 199.

Reaction Details 14 of 22
Reaction Classification Preparation
Reagent aqueous alkali
Other Conditions elektrolytische Oxydation an Eisen-Anoden
Note 1 Handbook
Ref. 1 1982322; Journal; Lowy; Moore; Trans.am.elektroch.Soc.; 42; 276,280; CHZEA6;

Chem.Zentralbl.; GE; 94; III; 1923; 1516.

Reaction Details 15 of 22
Reaction Classification Preparation
Yield 58 percent (BRN=472792)
Reagent Rhodococcus rhodochrous MTCC 289
Time 3 day(s)
Temperature 30 C
pH-Value 6.0
Reaction Type Oxidation
Ref. 1 6222516; Journal; Chatterjee, T.; De, B. K.; Bhattacharyya, D. K.; IJSBDB; Indian

J.Chem.Sect.B; EN; 38; 5; 1999; 538 - 541.

Reaction Details 16 of 22
Reaction Classification Preparation
Reagent aqueous alkali
Other Conditions elektrolytische Oxydation an Bleidioxyd-Anoden
Note 1 Handbook
Ref. 1 1982322; Journal; Lowy; Moore; Trans.am.elektroch.Soc.; 42; 276,280; CHZEA6;

Chem.Zentralbl.; GE; 94; III; 1923; 1516.

Reaction Details 17 of 22
Reaction Classification Preparation
Reagent air
 terpentine oil
Note 1 Handbook
Ref. 1 1523719; Froger-Delapierre; Patent DE150981.

Reaction Details 18 of 22
Reaction Classification Preparation
Reagent ozone
 sodium disulfite
Note 1 Handbook
Ref. 1 1523721; Spurge; Patent DE192565.

Reaction Details 19 of 22
Reaction Classification Preparation
Reagent alkali
Other Conditions Electrolysis
Note 1 Handbook
Ref. 1 1973055; Chem. Fabr. v. Heyden; Patent DE92007; FTFVA6;

Fortschr.Teerfarbenfabr.Verw.Industriezweige; DE; GE; 4; 1279.

Reaction Details 20 of 22
Reaction Classification Preparation
Reagent peroxidene
 alkali
Note 1 Handbook
Patent DE 93938
(http://l2.espacenet.com/espacenet/viewer?PN=DE93938&CY=gb&LG=en&DB=EPD)
haarmann & reimer
Fortschr.Teerfarbenfabr.Verw.Industriezweige; DE; GE; 4; 1277.

Reaction Details 21 of 22
Reaction Classification Preparation
Reagent manganese saltene
Note 1 Handbook
Ref. 1 1669893; Lang; Patent DE189178.



isoeugenole --> vanillin
nitrobenzene, aqueous KOH, 120-130C
Kimura; KGKZA7; Kogyo Kagaku Zasshi; 40; 1937; 600, 603;
Kimura; J. Soc. chem. Ind. Japan Spl.; 40; 1937; 277.

isoeugenole --> vanillin
acetic acid, air oxygen, ultraviolettes Licht.Irradiation
Patent DE224071; Genthe & Co.
FTFVA6; Fortschr.Teerfarbenfabr.Verw.Industriezweige; DE; GE; 9; 1130.

isoeugenole --> vanillin
air, an der gluehenden Platinspirale
Trillat; COREAF; C.R.Hebd.Seances Acad.Sci.; 133; 1901; 822; Trillat; BSCFAS;

Bull.Soc.Chim.Fr.; <3>29; 1903; 41.

isoeugenole --> vanillin
aqueous NaOH, 4-nitro-benzoic acid or
3-nitro-benzenesulfonic acid or 2-chloro-5-nitro-benzenesulfonic acid
Hoffmann-La Roche; Patent DE578037; 1931;
FTFVA6; Fortschr.Teerfarbenfabr.Verw.Industriezweige; DE; GE; 20; 534
 
isoeugenole --> vanillin
aqueous OsO4-solution
Hofmann; CHBEAM; Chem.Ber.; 45; 1912; 3336
Hofmann; CHZEA6; Chem.Zentralbl.; GE; 85; I; 1914; 199

isoeugenole --> vanillin
oxygen, terpenes
Patent DE150981; froger-delapierre

isoeugenole --> vanillin
hydrogen peroxide, V2O5 or CrO3, 2-methyl-propan-2-ol or 2-methyl-butan-2-ol
Ref. 1 1587093; Research Corp.; Patent US2402566; 1942.
Ref. 2 1587094; Research Corp.; Patent US2414385; 1942.
Ref. 3 519401; Journal; Milas; JACSAT; J.Amer.Chem.Soc.; 59; 1937; 2342.



eugenol --> vanillin
chem trade j and chem engr 3 (1925)



isoeugenole
 --> 1-(4-hydroxy-3-methoxy-phenyl)-propane-1,2-diol
 --> 2-hydroxy-1-(4-hydroxy-3-methoxy-phenyl)-propan-1-one
 --> 1-Hydroxy-1-(4-hydroxy-3-methoxy-phenyl)-propanon-(2)
 --> vanillin

30% H2O2, HOAc, solvent aq ethanol, 5h,
ambient temperature, further byproducts given
phytochemistry, 1990 29 5, 1653-1659; (english)
rupert kraus, gerhard spiteller
 
 
 
 
    3base
(Newbee)
06-04-02 20:32
No 317569
      benzaldehydes from cinnamic acids
(Rated as: excellent)
 Bookmark   

cinnamic acid --> benzaldehyde
potassium dichromate, diluted H2SO4
justus liebigs ann chem, 1839 31, 271; simon


cinnamic acid --> benzaldehyde
water, hydrogen peroxide, copper sulfate, 60C
bei einwirkung auf das natrium-salz
further products: carbon dioxide, formic acid, acetic acid
biochem j, 1935 29, 1877; jones, smedley-maclean


4-methoxycinnamic acid --> anisaldehyde
KMnO4 oxidation, yield 94%
synthesis, 2001 11, 1645-1648
"heterogeneous permanganate oxidation of styrene and cinnamic acid derivatives:
a simple and effective method for the preparation of benzaldehydes"
sheng lai, donald g. lee
abstract: styrene and cinnamic acid derivatives yield correspondingly substituted
benzaldehydes when oxidized by permanganate under heterogeneous conditions.
reaction of terminal aliphatic alkenes under similar conditions gives discouragingly
low yields; however, ketones and ketols are obtained in very good yields from the
oxidation of 2,2-disubstituted and trisubstituted alkenes, respectively. alumina and
amberlite IR-120 can be used as solid supports in these reactions with equally
good results.
../rhodium/chemistry /benzaldehydes.kmno4.html


sinapic acid --> syringaldehyde
autoclaving
journal of the american oil chemists' society, 1999 76(4), 433-441
"structural changes of sinapic acid and sinapine bisulfate during autoclaving"
with respect to the development of colored substances"
r cai, s d arntfield, j l charlton
abstract: structural changes in sinapic acid during autoclaving were studied using spectral
analysis, thin-layer chromatography, high-performance liquid chromatography, nuclear
magnetic resonance (NMR), and mass spectroscopy. color properties of sinapic acid and
its derivatives were studied by determining the transmittance spectrum, calculating the
commission internationale de l'eclairage 1931 tristimulus values and converting to hunter l
a b values. it was found that the colorless sinapic acid aqueous solution (100 g/mL) turned
yellow after 15 min in an autoclave at 121C and 0.1 MPa. filtering the yellow aqueous
solution through a 0.45-m filter removed a brown solid consisting of at least three
undetermined colored substances and left a yellow liquid. a newly developed yellow
substance, syringaldehyde, was identified in the liquid phase by comparing the NMR and
mass spectra of the unknown with those of authentic syringaldehyde. thomasidioic acid
was also found in the liquid phase. under the same autoclaving conditions, sinapine
bisulfate showed no evidence of any structural or color changes.


catalysed degradation of aqueous solutions of cinnamic acids
in the presence of TiO2 and UV radiation:

journal of environmental science and health part a- toxic/hazardous
substances & environmental engineering, 2001 36(5), 599-612
"PHOTOCATALYTIC DEGRADATION OF TRANS-CINNAMIC,
DIHYDROCINNAMIC, TRANS-CAFFEIC, AND DIHYDROCAFFEIC
ACIDS AND CHARACTERIZATION OF THE PRODUCTS"
Susan M. Grimes, Lina K. Mehta, Helen C. Ngwang
abstract: Catalysed degradation of aqueous solutions of cinnamic 1,
dihydrocinnamic 2, dihydrocaffeic 3 and trans-caffeic 4 acids in the presence of
(TiO2) and UV radiation and the products identified by HPLC, and after treatment
with diazomethane by GC-MS have been studied. A pH range of 3 to 11 was used.
The four acids, in the presence of TiO2 in the dark, underwent little degradation.
Extended irradiation of all the acids in the presence of TiO2 produced complete
degradation as shown by TOC measurements. Initially the volume of carbon
dioxide produced rose steadily to a constant value.

journal of environmental science and health part a- toxic/hazardous
substances & environmental engineering, 2001 36(10), 1891-1904
"CHEMICAL KINETICS OF THE PHOTOCATALYTIC DEGRADATION
OF TRANS-CINNAMIC, DIHYDROCINNAMIC, TRANS-CAFFEIC,
AND DIHYDROCAFFEIC ACIDS"
Susan M. Grimes, Lina K. Mehta, Helen C. Ngwang
abstract: Quantitative studies of the catalysed degradation of aqueous solutions
of cinnamic 1, dihydrocinnamic 2, trans-caffeic 3 and dihydrocaffeic 4 acids in
the presence of TiO2 and UV radiation at pH 3 and 10 are reported. The phenolic
and aliphatic unsaturated groups in caffeic acid 3 caused it to be adsorbed more
strongly than the phenolic saturated acid 4, and these two acids were much more
strongly adsorbed than cinnamic and hydrocinnamic acids. The kinetics of the
degradation of each acid has been studied at pH 3 and 10. TIC analysis showed
complete mineralisation of the acids after 9 h.


j chem soc perkin trans 2, 2001 (5), 793-797
"the reactions of ozone with cinnamic acids:
formation and decay of 2-hydroperoxy-2-hydroxyacetic acid"
Achim Leitzke , Erika Reisz , Roman Flyunt and Clemens von Sonntag
abstract: In aqueous solution, ozone reacts with 4-methoxycinnamate,
cinnamate and 4-nitrocinnamate with rate constants of 6.8 105, 3.8 105 and
1.2 105 dm3 mol-1 s-1, respectively. The corresponding acids react somewhat
more slowly. In product studies, material balance with respect to ozone
consumption has been obtained. In the case of cinnamic acid and its 4-methoxy
derivative, glyoxylic acid, H2O2 and the corresponding benzaldehydes are formed.
In contrast, 4-nitrocinnamic acid affords, besides a full yield of
4-nitrobenzaldehyde, 70% glyoxylic acid and 30% formic acid, while the H2O2
yield is also reduced to 70%. These results can be explained if in the latter case
the Criegee intermediate decomposes not only into glyoxylic acid and
1-hydroperoxy-1-phenylmethanol (which rapidly releases H2O2 yielding
4-nitrobenzaldehyde, k > 0.5 s-1), but also, to an extent of 30%, into
4-nitrobenzaldehyde and 2-hydroperoxy-2-hydroxyacetic acid. This product has
been produced independently by ozonating fumaric acid and has been shown
to decompose rapidly (k > 1 s-1) into formic acid and CO2. The reaction of H2O2
with the free carbonyl form of glyoxylic acid, present at 1.8% in equilibrium with
its hydrate, is comparatively slow (k = 0.3 dm3 mol-1 s-1, based on total glyoxylic
acid concentration). The reaction of the stronger nucleophile HO2-, present in basic
solutions, is considerably faster (k = 1700 dm3 mol-1 s-1). Thus, in the cinnamate
system, the substituents markedly influence the fate of the Criegee intermediate,
although they have only a small influence on the rate of the ozone reaction.
 
 
 
 
    3base
(Newbee)
06-04-02 20:51
No 317572
      benzaldehydes from styrenes  Bookmark   

oxidation with MnO2 and aq H2SO4
(1) methyl-isoeugenol --> veratric aldehyde; in the presence of sulphanilic acid
(2) anethol --> anisaldehyde; in the presence of sulphanilic acid
(3) styrene --> benzaldehyde
(5) b-methyl styrene --> benzaldehyde
(6) anethol --> anisaldehyde; with pyrolusite in the presence of sulphuric acid
and of sulphanilic acid
(7,8) methyl-isoeugenol --> veratric aldehyde; by a mixture of manganese dioxide
and sodium dichromate in the presence of sulphuric acid and sulphanilic acid
Patent GB774608, 1957-05-15, (equivalents: CH330121, DE1024500, FR1120496)
"a process for the preparation of aromatic carbonyl compounds from aryl ethylenes"
POLAK & SCHWARZ S ESSFNCEFABRI
 
 
 
 
    3base
(Newbee)
06-04-02 20:55
No 317574
      benzoic acids from styrenes  Bookmark   

cleavage of of styrenes under photoirradiation
synlett, 2002 3, 522-524
"oxidative cleavage of the double bonds of styrenes with a combination of
mesoporous silica FSM-16 and I2 under photoirradiation"
akichika itoh, tomohiro kodama, yukio masaki, shinji inagaki
abstract: a mesoporous silica FSM-16 was found to be a recyclable promoter for the
oxidative cleavage of double bonds, which are conjugated with an aromatic nucleus,
to afford the corresponding carboxylic acid in the presence of catalytic iodine under
photoirradiation conditions.


styrene --> benzoic acid
chemical communications, 1999 (1), 37-38
"heterogeneously catalysed cleavage of carbon-carbon double bonds with
hydrogen peroxide using calcined heteropolyacids on oxide supports"
christopher d. brooks , ling-chu huang , moya mccarron, robert a. w. johnstone
abstract: reaction of an alkene with aqueous hydrogen peroxide and a catalytic
quantity of a heteropolyacid adsorbed onto magnesium, aluminium or zinc oxide
leads to complete, rapid cleavage of the alkene to give carbonyl compounds.
 
 
 
 
    3base
(Newbee)
06-04-02 21:01
No 317578
      diol cleavage route  Bookmark   

isosafrole glycol --> piperonal
Patent JP60070193, 1985-04-20
"production of piperonal"
TORII SHIGERU; TAKASAGO KORYO KOGYO KK
PURPOSE: To produce piperonal at a high yield by electrolyzing isosafrole
glycol in an org. solvent or a solvent mixture composed of the org. solvent and
water in the presence of a specific electrolyte.
CONSTITUTION: The isosafrole glycol expressed by the formula ( I ), the
hydroxide, halide and carbonate of an alkali metal, the halide of an alkaline
earth metal and other electrolytes are put together with pentane, heptane,
octane and other org. solvents into a reaction vessel and are made into an
electrolyte. Water is added if necessary to the org. solvent in this case and
the isosafrole glycol is incorporated at 0.01-50% concn. into the electrolyte.
The electrolyte is so adjusted as to have 0.1-25% concn. An anode and
cathode formed of Au, Pt, stainless steel, etc. are dipped in the electrolyte
and after electrolysis is performed at 1-100A/cm2 current density, piperonal
is produced at a high yield by solvent extraction, distillation, etc. of the
conventional method.



C=C bond cleavage of aromatic diols in hexane under relatively mild conditions
journal of chemical research (synopses), 1998 (6), 308-309
"oxidation by chemical manganese dioxide.
part 1. facile oxidation of benzylic alcohols in hexane"
masao hirano, sigetake yakaba, hideki chikamori,
james h. clark, takashi morimoto
abstract: an inexpensive, stable, commercially available reagent, chemical
manganese dioxide, can be used for the oxidation of a wide variety of
benzylic alcohols and the C-C bond cleavage of aromatic diols in hexane
under relatively mild conditions.
 
 
 
 
    Rhodium
(Chief Bee)
06-04-02 23:20
No 317616
      Oxidation by Chemical Manganese Dioxide  Bookmark   

The latter article (MnO2 oxidation) is available free of charge here:

http://www.rsc.org/CFmuscat/intermediate_abstract.cfm?FURL=/ej/JC/1998/J9709079.PDF
 
 
 
 
    3base
(Hive Bee)
06-05-02 18:48
No 317874
      benzaldehydes from styrenes  Bookmark   

Patent GB774608, 1957-05-15, (Patent DE1024500)
this patent names some other nice refs for the preparation of benzaldehydes
from styrenes like anisaldehyde from anethol via oxidation by ozonizaion,
nitrobenzene, dichromate, ...
 
 
 
 
    3base
(Hive Bee)
06-05-02 19:11
No 317876
      isosafrole --> piperonal (V2O5, yield 67.4%)
(Rated as: excellent)
 Bookmark   

Piperonal from Isosafrole

Five grams of isosafrole (Eastman Kodak Company) was mixed
with 45 cc. of the peroxide reagent and to the mixture was
added 0.02 g. of vanadium pentoxide. As the catalyst dissolved,
the mixture heated up as before to almost the b. p. of the
solvent. The reaction was over in about two hours when
the mixture was still blood red due perhaps to the presence
of the addition complex between vanadium pentoxide and
piperonal.(12) The yield (67.4%) of piperonal, in this case,
was also estimated by precipitating its P-nitrophenyl-
hydrazone.(10) This P-nitrophenylhydrazone was recrystal-
lized twice from 95% ethyl alcohol, mp 202-203'. An
authentic sample prepared and purified in the same way had
a mp of 203-203.5; mixed mp showed no depression.
In another experiment in which 0.02 g. of chromium
trioxide was used as the catalyst, the yield of piperonal
was only 14%.

further procedures are given for:
   Isoeugenol --> Vanillin (yield 66%)
   Anethole --> Anisaldehyde (yield 55%)

J. Am. Chem. Soc.; 1937; 59(11); 2342-2344.
"The Hydroxylation of Unsaturated Substances.
III. The Use of Vanadium Pentoxide and Chromium Trioxide
as Catalysts of Hydroxylation"; Nicholas A. Milas
 
 
 
 
    Rhodium
(Chief Bee)
06-05-02 19:19
No 317877
      What is "the peroxide reagent"?  Bookmark   

What is "the peroxide reagent"?
 
 
 
 
    3base
(Hive Bee)
06-05-02 19:43
No 317882
      Re: What is "the peroxide reagent"?  Bookmark   

> What is "the peroxide reagent"?

hi rhodium, the paper says:

Vanadium Pentoxide

This catalyst may be obtained from the Vanadium Corporation of
America or it may be prepared in accordance with the
method described elsewhere(5) Vanadium pentoxide is
almost entirely insoluble in tertiary butyl or tertiary amyl
alcohol but, when the latter contains hydrogen peroxide,
it goes promptly into solution to form blood red pervanadic
acid(6) The reaction mixture, as a rule, remains blood
red until the end of the reaction when either the vanadium
pentoxide precipitates out as a dark brown solid, or re-
mains in solution as blue or green lower oxide. In every
case the catalyst may be rejuvenated easily by the addition
of more peroxide reagent.
 
 
 
 
    Rhodium
(Chief Bee)
06-05-02 21:28
No 317904
      Ok, so it is H2O2 in conjunction with V2O5 - but ...  Bookmark   

Ok, so it is H2O2 in conjunction with V2O5 - but there is no information on the concentration of H2O2, just "45ml" per 5g isosafrole.
 
 
 
 
    Bwiti
(PVC-Analog Taste-Tester)
06-07-02 09:30
No 318500
      Fuck ActiveX  Bookmark   

  What's up Rhodium?! I went to that link you provided, and I can't view it because I don't have an object handler called "ActiveX". The download page for this software at microsoft is fucked, it doesn't even tell me where else I can find this software. When I go to that link and try to view the full article, it says There is no viewer available for the type of object you are trying to open. Ive downloaded and ran about 8 different software programs. Dont have a clue what Im doing. Could someone please go to http://www.rsc.org/CFmuscat/intermediate_abstract.cfm?FURL=/ej/JC/1998/J9709079.PDF, copy it with maybe a screen-shot or something, then save it as a gif or jpg and post it on poppies.org or methinfo.com?   

  Check-out example 3 from GB774608

1920 grams of water and 617 grams of manganese dioxide of 66.9 % purity (4.75 mols) are introduced into a reaction flask.

The mixture is heated to 1000 C. and 208 grams (2.00 mols) of styrene are added.

A gentle stream of nitrogen is introduced into the apparatus and in 55 minutes a mixture of 2236 grams of water and 1118 grams of sulphuric acid cooled to room temperature is added at 100 C.

Stirring is continued for 1 hour 20'Sminutes at the same temperature. The reaction mixture is worked up and undistillable materials are discarded by a distillation in vacuum without the use of a column. In the distillate the components are identified by analytical methods. 28.8% of the styrene Introduced, 28.3% of the theoretical yield of benzaldehyde and 8.1% of the theoretical yield of benzoic acid are present The total yield of oxidation products is about 51% of the theoretical amount calculated on the converted starting material. By fractionation of the reaction product, benzaldehyde with the boiling point 90 C, at 42 torr, nD20 = 1.5440 and of 97.5 % purity is obtained.


  1000 C? I hope they meant to say 100 C! Anyway, with yields that lousy, then why not replace the styrene with an equimolar amount of toluene?
cool

Love my country, fear my government.
 
 
 
 
    Elementary
(Hive Addict)
06-07-02 11:22
No 318528
      Here you go  Bookmark   

You should be able to read it if you have acrobat reader installed.

Anyway I've converted it to jpeg's for you mate.

Here are the links

http://geocities.com/c6h5uk3/1.jpg
http://geocities.com/c6h5uk3/2.jpg

John Lennon - Working Class Hero
 
 
 
 
    Bwiti
(PVC-Analog Taste-Tester)
06-08-02 03:35
No 318729
      Cool  Bookmark   

  I already have acrobat reader. Love/Hate relationship with my computer. Thanks for converting it to a jpg! Much appreciated!cool

Love my country, fear my government.
 
 
 
 
    3base
(Hive Bee)
06-09-02 14:28
No 319101
      piperonal from isosafrole via ozonolysis  Bookmark   

isosafrole --> piperonal
ozonolysis, yield 87%
advan chem ser, 1958 21: 149; c a sublunskey et al
Patent US2776986; C.A., 1957 51: 8141
 
 
 
 
    pROcon
(Hive Bee)
06-12-02 01:11
No 319957
      Could one of you take a moment to explain to me ...  Bookmark   

Could one of you take a moment to explain to me why you pluralise the word benzaldehydes?

benzaldehyde is unambiguously C6H5CHO, synthetic bitter almond oil, no?

Or are aldehydes always pluralised when there s more than a single molecule?

don't call me...I wont answer, or call you back.
 
 
 
 
    Rhodium
(Chief Bee)
06-12-02 03:19
No 319995
      He is referring to that several different ...  Bookmark   

He is referring to that several different benzaldehydes can be made from several different styrenes, and that the reaction is not limited to a special variety of benzaldehyde.