- A Novel Synthesis of Monosubstituted Sulfines via an Unusual β-Elimination of Chloroform from Allylic and Benzylic Trichloromethyl Sulfoxides.
-
A new method for the synthesis of thioaldehyde S-oxides by base-induced elimination of chloroform from allylic and benzylic trichloromethyl sulfoxides is described.The reaction proceeds smoothly under mild conditions.A mechanism for this remarkable sulfin
- Braverman, Samuel,Grinstein, Dan,Gottlieb, Hugo E.
-
-
Read Online
- First insights into the mode of action of a "lachrymatory factor synthase" - Implications for the mechanism of lachrymator formation in Petiveria alliacea, Allium cepa and Nectaroscordum species
-
A study of an enzyme that reacts with the sulfenic acid produced by the alliinase in Petiveria alliacea L. (Phytolaccaceae) to yield the P. alliacea lachrymator (phenylmethanethial S-oxide) showed the protein to be a dehydrogenase. It functions by abstracting hydride from sulfenic acids of appropriate structure to form their corresponding sulfines. Successful hydride abstraction is dependent upon the presence of a benzyl group on the sulfur to stabilize the intermediate formed on abstraction of hydride. This dehydrogenase activity contrasts with that of the lachrymatory factor synthase (LFS) found in onion, which catalyzes the rearrangement of 1-propenesulfenic acid to (Z)-propanethial S-oxide, the onion lachrymator. Based on the type of reaction it catalyzes, the onion LFS should be classified as an isomerase and would be called a "sulfenic acid isomerase", whereas the P. alliacea LFS would be termed a "sulfenic acid dehydrogenase".
- He, Quan,Kubec, Roman,Jadhav, Abhijit P.,Musah, Rabi A.
-
experimental part
p. 1939 - 1946
(2012/01/13)
-
- Polyaromatic propynyl compounds and pharmaceutical/cosmetic compositions comprised thereof
-
Novel pharmaceutically/cosmetically-active polyaromatic propynyl compounds have the structural formula (1): STR1 in which X is one of the radicals: STR2 and are useful for the treatment of a wide variety of disease states, whether human or veterinary, for example dermatological, rheumatic, respiratory, cardiovascular and ophthalmological disorders, as well as for the treatment of mammalian skin and hair conditions/disorders.
- -
-
-
- A NOVEL SYNTHESIS OF THIOALDEHYDE S-OXIDES VIA AN UNUSUAL β-ELIMINATION OF CHLOROFORM FROM ALLYLIC AND BENZYLIC TRICHLOROMETHYL SULFOXIDES
-
A new method for the synthesis of thioaldehyde S-oxides including α,β-unsaturated derivatives, by mild base-induced elimination of chloroform from readily available allylic and benzylic trichloromethyl sulfoxides is described.
- Braverman, Samuel,Grinstein, Dan
-
p. 321 - 322
(2007/10/02)
-
- Thioaldehyde S-Oxide (Monosubstituted Sulfines) from Thioacylsilane S-Oxides. Synthesis and Fluorine- and Acid-Induced Z/E Isomerization. 2
-
Aromatic and aliphatic, not enethiolizable, thioaldehyde S-oxides (monosubstituted sulfines) are obtained from stereospecific fluorodesilylation of the corresponding thioacylsilane S-oxides with retention of configuration.A detailed investigation on the mechanism of the desilylation, as well as of the acid and fluoride ion induced Z/E interconversion has been performed.
- Barbaro, G.,Battaglia, A.,Giorgianni, P.,Bonini, B. F.,Maccagnani, G.,Zani, P.
-
p. 3744 - 3748
(2007/10/02)
-
- Synthesis and Isolation of Aryl Thioaldehyde S-Oxides
-
(E)-Phenyl and (E)-(p-tolyl) trimethylsilyl thioketone S-oxides can be easily and stereospecifically protodesilylated into the corresponding (Z)-aryl thioaldehyde S-oxides; these stable liquid lachrimatory compounds show good reactivity as heterodienophil
- Bonini, Bianca F.,Mazzanti, Germana,Zani, Paolo,Maccagnani, Gaetano,Barbaro, Gaetano,et al.
-
p. 964 - 965
(2007/10/02)
-
- Formation of α-Disulfoxides, Sulfinic Anhydrides, and Sulfines during the m-Chloroperoxybenzoic Acid Oxidation of Symmetrical S-Alkyl Alkanethiosulfinates
-
The m-chloroperoxybenzoic acid (MCPBA) oxidation of S-methyl methanethiosulfinate (33), S-propyl propanethiosulfinate (34), S-2-propyl 2-propanethiosulfinate (35), S-butyl butanethiosulfinate (36), and S-(phenylmethyl)phenylmethanethiosulfinate (37) has been at low temperatures and compared with the MCPBA oxidation of S-(2-methyl-2-propyl)-2-methyl-2-propanethiosulfinate (26) and S-(2,2-dimethylpropyl)-2,2-dimethylpropanethiosulfinate (30).Diastereomeric α-disulfoxides are observed with 33-36 at -40 deg C, sulfinic anhydrides are observed with 33, 35, and 36 at -40 deg C, and sulfines are observed on warming the product mixtures from 34-37 from -40 deg C to -20 deg C.The lachrymatory factor ((Z)-propanethial S-oxide, 47) of the onion was observed during the oxidation of 35.The absence of thiosulfonates at -40 deg C and their presence at higher temperature suggest that they are not formed in the initial oxidation process but from subsequent reactions of thiosulfinates and sulfinic acids.Various mechanisms for the formation of intermediates and products are discussed.
- Freeman, Fillmore,Angeletakis, Christos N.
-
p. 4039 - 4049
(2007/10/02)
-