Single-Step Synthesis of 1,2-Cyclopentanediones by Dehydrogenative Annulation of Ethylene Glycol with Secondary Alcohols.

Alcohol coupling reactions that are induced by alcohol dehydrogenation, and generate hydrogen or water as the only byproducts, have become a well-recognized way to carry out important synthetic transformations, such as esterification and alkylation, in a green and atom-economical fashion. Herein, we report a new type of alcohol-alcohol coupling reaction that involves the dehydrogenative annulation of ethylene glycol with secondary alcohols to give 1,2-cyclopentanedione derivatives in a single synthetic step. This process, which is catalyzed by a pincer complex of earth-abundant manganese, represents a new approach for constructing structurally complicated products from inexpensive, readily available alcohols.