The First Preparation of β‐Lactones by Radical Cyclization.

Abstract

Oxetane derivativesOxetane derivatives R 0035The First Preparation of β-Lactones by Radical Cyclization. -β-Lactones are prepared for the first time by 4-exo-trig radical cyclization of α-ethenoyloxy radicals. These radicals react in the presence of tributylstannane in a photothermal process to give the desired lactones. Highest yields are obtained when groups capable of stabilizing a carbon-centered radical are present at the 3-position of the alkenoate acceptor.-(CASTLE, K.; HAU, C.-S.; SWEENEY*, J. B.; TINDALL, C.; Org. Lett. 5 (2003) 5, 757-759; Dep. Chem., Univ. Reading, Whiteknights, Reading, Berkshire RG6 6AD, UK; Eng.) -Klein 29-095