Synthesis of Acyloxy‐Semicyclic Dienes Using an Enyne Metathesis/Ring Closing Metathesis Approach

Abstract

An enyne metathesis/ring closing metathesis (EM/RCM) sequence was used to synthesise acyloxy‐semicyclic dienes from an enyne substrate and various vinyl esters. This allowed convenient access to acyloxy‐semicyclic dienes not accessible by cross metathesis alone due to the low reactivity of Fischer carbenes with the termini of 1,3‐dienes. This new approach also provides an alternative method for the synthesis of 1‐acyloxy‐1,3‐dienes which are useful reactants for Diels–Alder cycloadditions.

Tandem cross enyne metathesis (CEYM)–intramolecular Diels–Alder reaction (IMDAR). An easy entry to linear bicyclic scaffolds

“…These inherent selectivity problems are absent when the olefin counterpart is the ethylene unit, which explains why most of the reported examples that combine a CEYM reaction with a Diels–Alder cycloaddition in a tandem manner involve the use of ethylene as the olefin partner either by employing an internal source of it or by bubbling it into the reaction mixture. This strategy allowed for the synthesis of a wide variety of natural and non-natural products in the last decade [ 12 – 22 ].…”