Oxyanionic Sigmatropic Rearrangements Relevant to Cyclooctadienone Formation in Penostatins I and F

Abstract

The results of several experiments designed to probe the energetic viability of a reaction path for generation of penostatins I (<b>3</b>) and F (<b>4</b>) via spontaneous [3,3]-sigmatropic rearrangement are reported. In particular, the enolate derived from the 2-vinyl-6-acyldihydropyran <b>8-cis</b> gave cyclooctadienone <b>12</b> via facile anionic oxy-Claisen rearrangement, demonstrating the feasibility of such an event