Cobalt-catalyzed cycloisomerization of 1,6-enynes and allyl propargyl ethers.
[reaction: see text] 1,6-Enynes and allyl propargyl ethers undergo a cobalt-catalyzed formal 5-endo-dig cyclization to form vinyl cyclopentenes and dihydrofurans, respectively. The use of equimolar amounts of dicobalt octacarbonyl and trimethyl phosphite affords optimum yields and improved selectivity for cycloisomerization vs alkene isomerization.
Ajamian
Alain
A
Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, Quebec, Canada, H3A 2K6.
Gleason
James L
JL