An ynolate-initiated tandem process giving cyclopentenones: total synthesis of cucumin E

A total synthesis of cucumin E, a novel type of triquinane natural product, has been accomplished. The strategy is based on an ynolate-initiated tandem [2+2] cycloaddition-Dieckmann condensation, followed by decarboxylation, giving cyclopentenones. (C) 2002 Elsevier Science Ltd. All rights reserved.