Abstract
This chapter highlights a number of inventive and functional synthetic strategies, which have employed chiral auxiliaries to control stereoselectivity, with notably more success compared to their achiral counterparts in glycosylation reactions. The synthesis of 1,2‐trans glycosides can be achieved with complete stereoselectivity by virtue of neighboring group participation (NGP). One of the most elegant and imaginative solutions to the problems posed by stereoselective glycoside synthesis was an O‐2 chiral auxiliary‐based approach first disclosed by Boons and coworkers in 2005. Boons' second‐generation auxiliary attempted to improve on the ethyl mandelate ether by utilizing a (1S)‐phenyl‐2‐(phenylsulfanyl) ethyl chiral auxiliary where the aryl sulfur moiety acted as the intercepting nucleophile in lieu of a carbonyl. A number of thioglycoside activation strategies were screened in initial glycosylation reactions using the oxathiane ketals. The myriad of different glycosylations required to synthesize even a fraction of these structures place restrictions on the extent to which these strategies can be considered general.
Original language | English |
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Title of host publication | Selective Glycosylations: Synthetic Methods and Catalysts |
Editors | Clay Bennett |
Publisher | Wiley-Blackwell |
Pages | 97-112 |
ISBN (Electronic) | 9783527696239 |
ISBN (Print) | 9783527339877 |
Publication status | Published - 27 Jan 2017 |