An ortho-Quinodimethane Route to Lasofoxifene and U23469

摘要

Lasofoxifene, a third-generation selective estrogen receptor modulator, could be synthesized via regio- and stereoselective [4 + 2] cycloaddition between an ortho-quinodimethane and a borylalkene. This protocol was also applicable to the synthesis of antiestrogen U23469.