structure–activity study of a bioactive natural product containing polypropionate subunits requires that its stereoisomers also be evaluated. Therefore, a general approach to synthesize these motifs is necessary. We describe herein the synthesis of the C1–C13 polypropionate subunit of zincophorin and isomers thereof using a two-reaction sequence: an aldol reaction using a mixture of tetrasubstituted enoxysilanes
Synthesis of 2,3-Anti-3,4-anti and 2,3-Anti-3,4-syn Propionate Motifs: A Diastereoselective Tandem Sequence of Mukaiyama and Free-Radical-Based Hydrogen Transfer Reactions
[reaction: see text] Reported herein is a strategyemploying a Mukaiyama reaction in tandem with a hydrogentransferreaction for the elaboration of 2,3-anti-3,4-anti and 2,3-anti-3,4-syn propionate motifs. The mode of complexation is controlled through monodentate or chelate pathways for the Mukaiyama reaction to give access to either syn or anti aldol products, precursors of the free-radical reduction
Reported herein is the iteration of a strategy employing a Mukaiyama reaction in tandem with a hydrogen transfer reaction for the elaboration of four polypropionate motifs containing the anti-anti unit. In this process, Lewis acid acts as the key element in controlling the diastereoselectivity of each step, the outcome of which is >20:1 for all of the reactions performed. (C) 2002 Elsevier Science Ltd. All rights reserved.