In situ prepared ketene acetals of γ-hydroxyvinyl sulfones undergo a Claisenrearrangement affording 3-phenylsulfonyl esters. These compounds are converted to (2E,4E)-dienoic esters by a base-assisted elimination of benzenesulfinic acid.
The synthesis of a C1-C14 fragment of a marine cytotoxic natural product Palmerolide A is described. The key steps involved in this synthesis are deoxygenative rearrangement of an alkynol followed by an asymmetric dihydroxylation of a diene ester and CBS-reduction. (c) 2007 Elsevier Ltd. All rights reserved.