Approaches toward the synthesis of 2,5‐disubstituted‐1,3‐thiazolidines

Abstract

Synthetic approaches for new 2,5‐disubstituted‐1,3‐thiazolidines are described. Steric and electronic effects of the N‐substituent of the thiazolidine ring represent the major parameter in the rearrangement process. The nmr studies demonstrate that N‐unsubstituted 2,5‐disubstituted‐1,3‐thiazolidines exist as epimeric mixture, while the corresponding N‐acetylated analogues exist as a conformer mixture.

Chemical Synthesis of Heterocyclic−Sugar Nucleoside Analogues

“…The Pummerer rearrangement resulted in an adequate approach to prepare thiazolidine precursors 311 needed for the synthesis of nucleosides bearing a hydroxymethyl group like compounds 312 (Scheme 83). 126 Condensation of 311 with persilylated bases in the presence of SnCl 4 afforded mixtures of cis and trans nucleoside analogues. 127 Starting from formyl pyrimidine 313, 1,3-thiazolidinyl analogues of pseudouridine have been prepared by Bessho et al 128 The formation of the thiazolidine ring was performed in a enantiodivergent way by using either D-or L-cysteine (only the L-series is showed in Scheme 84).…”

“…The Pummerer rearrangement resulted in an adequate approach to prepare thiazolidine precursors 311 needed for the synthesis of nucleosides bearing a hydroxymethyl group like compounds 312 (Scheme ) . Condensation of 311 with persilylated bases in the presence of SnCl 4 afforded mixtures of cis and trans nucleoside analogues…”

Synthesis and stereoselective functionalization of silylated heterocycles as a new class of formyl anion equivalents

“…75 Recently, a number of thiazolidines have been claimed to be retroviral protease inhibitors 75b, 76 and have also been investigated as possible substitutes for the carbohydrate moiety in the synthesis of new antiviral nucleosides. 77 More recently, they have also been shown to be antitussive-active molecules. 78 Thiazolidines are also relevant in food chemistry as they are incorporated into flavor enhancing additives.…”

A General Access to 2-Silylthiazolidines and Their Reactions Under Fluoride Ion Conditions

“…Substituted thiazolidine derivatives represent important key intermediates for the synthesis of pharmacologically active drugs [3]. Recently a number of thiazolidines have been claimed to be retroviral protease inhibitors [3b,4] and have also been investigated as possible substitute for the carbohydrate moiety in the synthesis of new antiviral nucleosides [5]. More recently they have also been shown as antitussive active molecules [6].…”