TETRAHYDROFURAN AS AN ONE-ELECTRON DONOR - HIGHLY DIASTEREOSELECTIVE COUPLING OF COBALT-COMPLEXED PROPARGYL ALCOHOL

A novel one-step reductive dimerization of Co-complexed propargyl alco hol 5 has been developed producing dl- and meso-(3,4-diphenyl-1,5-hexa diyne)-bis-dicobalt hexacarbonyl (8,9) with unprecedented diastereosel ectivity of 90%. A tandem action of a variety of one-electron/hydride ion donors and Bronsted Lewis acids has been tested both in one-and tw o-step methods with the latter including the isolation of propargyl ca tion 1. (C) 1997 Elsevier Science S.A.