32157-29-2

Usage

Physical state

Colorless liquid.

Odor

Sharp, garlic-like.

Solubility

Soluble in water and most organic solvents.

Common uses

Flavoring agent and fragrance in the food and cosmetic industries.

Potential applications

Pharmaceuticals and organic synthesis.

Health benefits

Antioxidant and anti-inflammatory properties (further research needed).

Precautions

Can be irritating to the skin, eyes, and respiratory system.

Upstream product

• 1948-52-3 propyl propylthiosulfinate 
• 23267-68-7 propane-1-sulfinyl chloride 
• 232265-53-1 2-methyl-2-propyl 1'-propenyl sulfoxide 

Relevant academic research and scientific papers

Allium chemistry: Microwave spectroscopic identification, mechanism of formation, synthesis, and reactions of (E,Z)-propanethial S-oxide, the lachrymatory factor of the onion (Allium cepa)

Flow pyrolysis of 2-methyl-2-propyl 1'-propenyl sulfoxide (9b) affords a 98:2 mixture of (Z)- and (E)-propanethial S-oxide ((Z)- and (E)-5b), both characterized by Fourier transform microwave (FT-MW) spectroscopy. Sulfines (Z)- and (E)-5b are also identified by FT-MW in chopped onion volatiles and by NMR spectroscopy in onion extracts. Similarly, flow pyrolysis of 2-methyl-2-propyl vinyl sulfoxide (9c) affords (Z)- and (E)-isomers of ethanethial S-oxide (5a), identified by FT-MW methods. Pyrolysis in the presence of D2O affords (Z)-5a-d1 and (Z)-5a-d2 from 9c and (Z)-5b-d1 from 9b; (Z)-5b-d1 is also produced when an onion is homogenized in D2O. Pyrolysis of 9c with ethyl propiolate gives ethyl (E)-3-(vinylsulfinyl)acrylate (10). Neat 5a at 100°C gives acetaldehyde. On standing, 5b dimerizes to trans-3,4-diethyl-1,2-dithietane 1,1-dioxide (12a); Me3SiCH=S+-O- (5f) undergoes an analogous dimerization. Compound 5b shows moderate potency as an anticarcinogen in inducing the enzyme quinone reductase.

Discovery of overlooked enzyme in onion and its application

When onions (Allium cepa) are chopped, cells are broken, propanthial S-oxide (lachrymatory factor; LF) is released and it makes our eyes water. LF had long been believed to be formed non-enzymatically from 1-propenesulfenic acid (PSA), a putative reaction product of alliinase acting on trans-(+)-S-(1-propenyl)-L-cysteine sulfoxide (1-PRENCSO). During the course of our study for the discoloration of Allium plants, however, we got a clue that some unknown enzyme responsible for the LF formation should be present in the crude onion alliinase preparation. In this study, we report the discovery of this new enzyme called lachrymatory factor synthase (LFS), and its application such as non-lachrymatory onions.

REAGENT FOR LACRIMATION EXAMINATION AND METHOD OF LACRIMATION EXAMINATION

A new application of the dacryogenic component of onions and analogues of the component in the medicinal field. It is a reagent for lacrimation examination which contains as an active ingredient a compound represented by the following chemical formula: wherein R represents a C1-5 alkyl chain.

2-Thiabicyclohept-5-ene and Its S-Oxides and 3-Alkyl Derivatives: Sulfine and Sulfene Cyclopentadiene Diels-Alder Adducts. Conversion of the Cyclopentadiene-Sulfine Adducts into 2-Oxa-3-thiabicyclooct-7-enes, Novel Bicyclic Sultenes

Reaction of (trimethylsilyl)methanesulfonyl chloride (6a) or -sulfonic anhydride (6b) with cesium fluoride in the presence of cyclopentadiene affords 2-thiabicyclohept-5-ene 2,2-dioxide (4) by way of sulfene CH2=SO2.Similar reaction of (trimethylsilyl)methanesulfinyl chloride (7) gave unstable 2-thiabicyclohept-5-ene endo-2-oxide (3) via the intermediacy of sulfine CH2=SO.Compound 3 can be oxidized to 4 and reduced to 2-thiabicyclohept-5-ene (1) and the latter oxidized to the stable 2-thiabicyclohept-5-ene exo-2-oxide (2).Fluorodesilylation of 1-(trimethylsilyl)propanesulfonic anhydride (8) in the presence of cyclopentadiene gave a 77/23 ratio of endo/exo-3-ethyl-2-thiabicyclohept-5-ene 2,2-dioxide (9a/b) by way of propanethial S,S-dioxide.The structure of the major isomer 9a was established by an X-ray structure of the corresponding exo-epoxide 11a, formed from 9a by oxidation.Reaction of 4 with n-butyllithium followed by ethyl iodide gave a compound identical with minor isomer 9b.Reaction of propanethial S-oxide with cyclopentadiene gave unstable endo-3-ethyl-2-thiabicyclohept-5-ene endo-5-oxide (10a).The structure of 10a was established by oxidation to sulfone 9a, by reduction and reoxidation to a stable exo-5-oxide 10b, by its facile sigmatropic rearrangement to exo-4-ethyl-2-oxa-3-thiabicyclooct-7-ene (14c), and by NMR spectroscopic methods.Compound 14c was characterized by NMR spectroscopy and by its reactions.Oxidation of 14c gave the endo/exo-3-oxides 15c/15c' and the 3,3-dioxide 16c.Reaction of 14c with phenyllithium gave alcohol 17c, which was desulfurized and oxidized to 5-propyl-2-cyclopentenone or was oxidized at both carbon and sulfur to give (E)-5-propylidene-2-cyclopentenone 21c on gentle warming.Reaction of 14c with tert-butyl alcohol gave exo-6-tert-butoxy-exo-3-ethyl-syn-7-hydroxy-2-thiabicycloheptane (24), characterized by further oxidation to crystalline hydroxy sulfone 25 and keto sulfone 26.Mechanisms are proposed for the above series of reactions.

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.