Concise approach to the core of englerin A via an organocatalytic [4+3] cycloaddition reaction

A concise enantioselective synthesis of diversely functionalized advanced intermediates comprising the tricyclic skeleton of englerin A and related oxygen-bridged guaianes has been successfully accomplished, which features a Harmata organocatalytic [4+3] cycloaddition reaction. (C) 2010 Elsevier Ltd. All rights reserved.