A Domino Strategy for the Synthesis of 2H‐Pyrans from Propargyl Vinyl Ethers

Abstract

Stable monocyclic 2H‐pyrans are synthesized from readily available tertiary propargyl vinyl ethers via a metal‐free all‐pericyclic domino manifold involving a sequential propargyl Claisen rearrangement/[1,3]H‐shift/oxa‐6π electrocyclization set of reactions. The wide scope of this protocol is exemplified by the synthesis of 21 different 2H‐pyrans incorporating a varied substitution pattern at the ring.