Studies of a proposed mechanism for the reaction between 2H‐pyran‐2‐ones and organomagnesium compounds

Abstract Part of the reaction between 2H‐pyran‐2‐ones and organomagnesium compounds has been investigated by means of MNDO and ab initio calculations. Criteria for the mechanism of reaction are provided by the stereoselectivity observed and calculations are consistent with this stereoselectivity. Conformations of the reaction intermediates are given.