An Unconventional Approach to the Enantioselective Synthesis of Caryophylloids

摘要

Since the appearance of the unusual 4/9-fused ring nucleus of β-caryophyllene (1), many natural products have been discovered that either contain or are derived from this subunit, for instance antheliolide A (2) and coraxeniolide A (3). This whole family of caryophylloids has presented a real challenge to synthetic chemistry, and most members have either not been synthesized or been made only recently. We describe herein a novel strategy for the synthesis of caryophylloids, which depends on the accessibility of the hitherto unknown chiral dienone 4 and its enantiomer, ent-4.