Pd-catalyzed formal [2+2]-retrocyclization of cyclobutanols via two-fold Csp3–Csp3 bond cleavage

Abstract

In this work we describe the unexpected two-fold Csp3–Csp3 bond cleavage suffered by cyclobutanols in the presence of a catalytic amount of Pd(OAc)2 and promoted by the bulky biaryl JohnPhos ligand. Overall, the sequential cleavage of a strained and an unstrained Csp3–Csp3 bond leads to the formal [2+2]-retrocyclization products, namely, styrene and ace- tophenone derivatives. This procedure might enable the use of cyclobutanols as masked acetyl groups resisting harsh condi- tions in organic synthesis.