Abstract
The trans-fused tetrahydroindanone ring system 6 can be synthesized by intramolecular Diels–Alder cycloaddition of activated triene 5. The preparation of this intermediate is readily promoted by the LIC-KOR-promoted metalation of crotonaldehyde dimethyl acetal.
ACKNOWLEDGMENTS
One of us (PV) warmly thanks Dr. J. Maddaluno (Université de Rouen/IRCOF) for helpful discussion and suggestions. We also thank Prof. M. Mella (Dipartimento di Chimica Organica, Università di Pavia) for her expertise with NMR spectra. This work was supported by a grant from Italian MURST.