Stereoselective Cyclizations and Rearrangements in Vinyl Radicals Promoted by Regioselective Sulfanyl Radical Addition to Enynes

PC Montevecchi, ML Navacchia

Index: Montevecchi, Pier Carlo; Navacchia, Maria Luisa Journal of Organic Chemistry, 1997 , vol. 62, # 16 p. 5600 - 5607

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Citation Number: 20

Abstract

Regioselective radical addition of 4-cyanotoluenethiol (1a) to enynes 3-6 leads to vinyl radicals 7-10 that can undergo five-or six-membered cyclization onto styrene or terminal double bonds in competition with 5-exo cyclization onto the aryl ring. The latter affords spiro- cyclohexadienyl radical intermediates which can either be trapped by 2-cyanoisopropyl radicals or give 1, 4-aryl migration products. Regioselective radical addition of ...