Use of methyl 2-iodo-2-(phenylsulfonyl)-4-pentenoate in atom-transfer radical cyclizations. Entry into annulation products containing carbonyl or exo-methylene functionality

Article abstract of DOI:10.1016/S0040-4039(00)60165-X

Methyl 2-iodo-2-(phenylsulfonyl)-4-pentenoate (8) is reacted with N-BOC-allylamine to afford substituted 3-azabicyclo-[3.3.0]octanes (10) in a process which involves an initial iodine atom-transfer annulation followed by an ionic cyclization. The geminal carbomethoxy and phenylsulfonyl groups are then efficiently converted to either an exocyclic olefin or to a carbonyl group. The latter transformation allows phenylsulfonylacetates to be used as surrogates for acyl radicals in synthesis.