Synthesis of Naphthols by Rh(III)-Catalyzed Domino C-H Activation, Annulation, and Lactonization Using Sulfoxonium Ylide as a Traceless Directing Group

Sulfoxonium ylide directed C-H activation catalyzed by the Rh(III)-catalyst has been disclosed. In this study, sulfoxonium ylide functions as a traceless directing group, which reacts with an unsymmetrical alkyne, 4-hydroxy-2-alkynoate, to form the corresponding furanone-fused 1-naphthols. The application of the methodology has been illustrated by synthesizing bromo lactones, which are used as an intermediate in synthesizing photochromic dichroic materials. We have also demonstrated the synthesis of an analogue of fimbricalyx lactone A.