The photochemical reaction of Os 3(CO) 10(μ-H)(μ- γ-C 5H 3O 2), a triosmium cluster carrying a γ-pyrone ligand, with dimethylacetylenedicarboxylate: Formation of isomeric clusters

Abstract

The reaction of the cluster Os 3(CO) 10(μ-H)(μ- γ-C 5H 3O 2) (1), with DMAD under UV irradiation afforded three isomers of the monosubstituted product, Os 3(CO) 9(μ-γ-C 5H 3O 2)(μ 3-MeO 2CCHCCO 2Me) (2), and a disubstituted product, Os 3(CO) 8(μ-γ-C 5H 3O 2)(μ 3-MeO 2CCHCCO 2Me)(μ-MeO 2CCCCO 2Me) (3). The formation of 3 suggests that flipping of the O-heterocycle can occur. © 2004 Elsevier B.V. All rights reserved.