Further studies on cation clock reactions in glycosylation: observation of a configuration specific intramolecular sulfenyl transfer and isolation and characterization of a tricyclic acetal.

ABSTRACT: The use of the 2-O-(2-trimethylsilylmethallyl) group as intramolecular nucleophile and cation clock reaction in the glucopyranose series depends on the nature of the glycosyl donor. As previously reported, with trichloroacetimidates the anticipated intramolecular Sakurai reaction proceeds efficiently and is an effective clock, whereas with sulfoxides complications arise. The source of these complications is now shown to be an intramolecular sulfenyl transfer reaction between the tethered allylsilane and the activated sulfoxide. These results illustrate how a different unimolecular clock reaction may be required for a given cation when it is generated from different donors in order to avoid side reactions. The synthesis and cyclization of a 2-O-(3-hydroxypropyl) glucopyranosyl sulfoxide lea

SUBMITTER: Huang M 

PROVIDER: S-EPMC4860153 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature