158060-54-9

Upstream product

• 144409-56-3 (R,R)-(+)-1,3-dithiane-1,3-dioxide 
• 2043-61-0 cyclohexanecarbaldehyde 

Downstream Products

• 199989-08-7 (1S)-tetrahydropyran-(2RS)-2-yl [1-cyclohexyl-(1R,3R)-1-(1,3-dithiane-1,3-dioxide-2-yl)]methyl ether 

Relevant academic research and scientific papers

trans-1,3-Dithiane-1,3-Dioxide, a New Chiral Acyl Anion Equivalent for the Preparation of Masked Activated Acids: Application to the Synthesis of α-Hydroxy Acid Derivatives

trans-1,3-Dithiane-1,3-dioxide reacts with high diastereoselectivity with aromatic aldehydes and the 1,3-dithiane-1,3-dioxide moiety can be easily converted to a thiolester without racemisation by carrying out a Pummerer reaction; the thiolester is a group that can be readily transformed into acids, esters, amides, ketones and aldehydes.

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.