Total Synthesis of (±)-Pestalachloride C and (±)-Pestalachloride D through a Biomimetic Knoevenagel/Hetero-Diels-Alder Cascade

A concise total synthesis of (+/-)-pestalachloride C and (+/-)-pestalachloride D was achieved through a Knoevenagel/hetero-Diels-Alder cascade reaction to test the nonenzymatic biosynthetic hypothesis of Shao, Wang, and co-workers. The cascade reaction generates a mixture of racemic indano[2,1-c]chromans like those found in the natural products.