The Synthesis, Structural Characterisation and Chemical Manipulation of the [6+3] Cycloadduct Derived from α‐Tropolone O‐Methyl Ether and Trimethylenemethane

Abstract

The title bicyclic system 3, the adduct arising from the formal [6 + 3] cycloaddition of α-tropolone O-methyl ether (1) and trimethylenemethane (2), has been prepared and subject to single-crystal X-ray analysis. The chemical manipulation of adduct 3 in a range of ways is reported, including through acid-catalysed rearrangement of the derived mono-oxide to give the bicyclo[4.3.1]undecane 21. Scheme 1. The previously reported [3] [6 + 3] cycloaddition of troponoid 1 with TMM (2) leading to adduct 3.