Base‐Mediated Sequential Annulation Reaction of Conjugated Dienes and Crotonate‐derived Sulfur Ylides：Effective Synthesis of Bicyclo[4.1.0]heptenes

Herein we present a method for base‐mediated sequential annulation reaction of conjugated dienes. The method offers an efficient pathway for the effective construction of bicyclo[4.1.0]heptenes. Notable features of this approach include good yields, remarkable stereoselectivity, as well as a broad substrate scope and significant step efficiency. In addition, the reaction could be effectively scaled up to a gram scale under standard condition.