199870-84-3

Upstream product

• 214899-24-8 (+)-diethyl [(1R,3R)-1,3-dioxo-1,3-dithian-2-yl]phosphonate 
• 2043-61-0 cyclohexanecarbaldehyde 
• 144409-56-3 (R,R)-(+)-1,3-dithiane-1,3-dioxide 
• 95680-13-0 2-cyclohexylmethylidene-1,3-dithiane 

Relevant academic research and scientific papers

Highly enantioselective oxidations of ketene dithioacetals leading to trans bis-sulfoxides

Ketene dithioacetals undergo a Sharpless-type asymmetric oxidation using (+)-DET, Ti(OZPr)4, and cumene hydroperoxide to give the trans bis-sulfoxides 4a-f with essentially complete control of enantioselectivity and dia-stereoselectivity. The high enantio

Diastereomerically pure spirocyclic bis-sulfinyl oxiranes and their application to the asymmetric synthesis of α-amino amides

Optically pure spirocyclic bis-sulfinyl oxiranes 4 have been prepared and converted in a single step into α-amino amides.

trans-1,3-dithiane-1,3-dioxide; a chiral acyl anion equivalent. Enantioselective synthesis of α-hydroxy- carboxylic acids, esters, amides and ketones

The reaction of (R,R)-(+)-1,3-dithiane-1,3-dioxide with aldehydes has been carried out and the dithiane dioxide moiety elaborated further. (R,R)-(+)-1,3-Dithiane-1,3-dioxide gave highly diastereoselective addition products with benzaldehyde and 3,4- dimethoxybenzaldehyde and single diastereomers were isolated in 84 and 76% purified yields respectively. Under similar conditions cyclohexane carboxaldehyde gave an easily separable mixture of diastereomers in 86% total isolated yield. The adducts were transformed into protected S- ethyl α-hydroxythioesters in 95-100% ee via a Pummerer reaction and subsequent trans-thioesterification protocol using LiSEt. Using LiSEt little racemisation occurred even with aryl substituted thioesters. Further transformations of thioesters to various α-hydroxy carboxylic acid derivatives (acids, esters, amides) without racemisation have been achieved. The approach resulted in the synthesis of the dimethyl ether of (R)-(-)-3,4-dihydroxymandelic acid in its naturally occurring form. Addition of dibutyl cuprate (derived from BuMgBr and Cu(I)Br) to the thioester gave the corresponding ketone in high yield and again without racemisation.

Stereoselective epoxidation of bis-sulfinyl alkenes and application to the asymmetric synthesis of α-substituted carboxylic acids

Ketene thioacetals 3 can be easily prepared in optically pure form and react diastereoselectively with metal peroxides. The resulting bis-sulfinyl oxiranes can be converted in a single step to α-substituted acids.