Acid-Catalyzed Stevens Sigmatropic Rearrangement of N-Allylhydrazones

Significance

The construction of C-C bonds through sigmatropic rearrangements can be a useful and a non-obvious strategy in synthesis. In this work, the authors explore the acid-catalyzed Stevens [3,3]-sigmatropic rearrangement. The ­described transformation proceeds with moderate to good yields. A variety of E-alkenes are generated in diastereoselectivity of up to 20:1.

Review: For a review on Stevens rearrangement, see: R. V. Stevens, E. E. McEntire, W. E. Barnett, E. Wenkert Chem. Commun. 1973, 662-663.