A Paternò−Büchi Approach to the Synthesis of Merrilactone A

Abstract

A six-step approach to the tetracyclic core of merrilactone A is described that uses an intramolecular Paterno-Büchi photoaddition to install the key oxetane ring. Irradiation of bicyclic enone 16, constructed through cyclopentenone alkylation followed by a domino oxy-/carbopalladation reaction, produces the tetracyclic oxetane 17 in excellent yield, having the core carbon skeleton of the target compound merrilactone A. [reaction: see text]