Synthesis of the C10-C17 fragment of aurisides and callipeltosides

The key unsaturated chiral C10-C17 fragment common on the synthesis of aurisides and callipeltosides was synthesized in six steps from 5-bromopentadienal via aldol condensation with Nagao's chiral auxiliary and further manipulation using Ohira's reagent and Negishi's carboalumination-iodination. (C) 2002 Elsevier Science Ltd. All rights reserved.