Highly Diastereoselective, Tandem, Three‐Component Synthesis of Tetrahydrofurans from Ketoaldehydes via Silylated β‐Lactone Intermediates

Like falling dominoes! A novel tandem, three-component reaction is described that generates up to two CC bonds, one CO bond, and three additional stereocenters leading to substituted tetrahydrofuran units. This process involves a tandem Mukaiyama aldol-lactonization/reductive cyclization and proceeds via a silylated β-lactone intermediate. The method was applied to prepare the tetrahydrofuran fragment of colopsinol B. Py=2-pyridyl.