Extending the Scope of the [2+2] Cycloaddition of Dichloroketene to Chiral Enol Ethers: Synthesis of (-)Detoxinine

Allylic oxidation of a known lactam, obtained by asymmetric [2+2] cycloaddition of dichloroketene to a chiral enol ether, followed by Beckmann ring expansion and dechlorination, affords a potential intermediate for the synthesis of various natural products. The usefulness of this intermediate is first demonstrated by an asymmetric synthesis of (-)-detoxinine.