Towards a simplified peloruside A: synthesis of C1–C11 of a dihydropyran analogue

A simplified analogue of the C1–C11 fragment of peloruside A has been synthesised starting from a monoprotected 2,2-dimethylpropane-1,3-diol. Oxidation, asymmetric allylation and acryloylation provided a substrate for ring-closing metathesis to a δ-lactone. Reduction, acylation and homologation with trimethyl(vinyloxy)silane provided a protected C3–C11 analogue in a stereoisomer manner. Introduction of the C1–C2 fragment and incorporation of the 2,3-syn stereochemistry was achieved by a boron-mediated Evans aldol reaction.