ol034985b_si_002.cif (35.25 kB)

Formal Intermolecular 4 + 4 Approach to Cyclooctanoids:  4 + 3 Capture of the Nazarov Oxyallyl Intermediate with Simple 1,3-Dienes

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posted on 19.06.2003, 00:00 by Yong Wang, Brenden D. Schill, Atta M. Arif, F. G. West
Simple 1,4-dien-3-ones and 1,3-dienes react in the presence of BF3·OEt2 via a domino Nazarov electrocyclization/intermolecular [4 + 3]-cycloaddition sequence to furnish keto-bridged cyclooctenes in good yield. Most cases showed high diastereofacial selectivity and/or endo/exo selectivity, and surprising levels of regioselectivity were observed when isoprene was used as the diene partner.