α-Ketene alkyl and α,β-unsaturated acyl radical intermediates in ring constructions

Article abstract of DOI:10.1016/0040-4039(95)02147-7

Treatment of the E-α,β-unsaturated selenyl esters and 1 and 3a with Bu₃SnH-AIBN produces the corresponding cyclohexones 2 and 7/8 respectively via presumed α-ketene alkyl radical intermediates. In a similar manner the cyclopropyl ester 9 leads to a mixture of 12 and 13, and the 2,7-diene selenyl ester 15 undergoes a novel bi-cyclisation producing the diquinane 17 in 76% yield.