Weinreb amide based building blocks for convenient access to analogues of phenstatin

Bifunctional synthetic equivalents containing a Weinreb amide as one of the functionalities have been synthesized from commercially available o-, m-, and p-toluic acid. These bifunctional building blocks enabled efficient C-C bond formation through Wittig reaction with simple and functionalized aldehydes on one hand and a clean nucleophilic addition of 3,4,5-trimethoxy phenylmagnesium bromide onto the Weinreb amide functionality on the other hand, therebypaving way for an efficient and convenient synthesis of novel analogues of phenstatin with highly functionalized appendages. Further addition of various aryl or heteroarylmagnesium bromides onto theWeinreb amide functionality provided a general strategy for synthesizing unsymmetrical diaryl ketones conjugated to a monosaccharide moiety for the first time. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.