A Study of Claisen Rearrangements Of (1,1-Dimethyl-3-Prop-2-Ynyloxy)--1-Benzopyran-4-One Derivatives

Article abstract of DOI:10.1016/S0040-4020(01)89017-7

The Claisen Rearrangements of 7-(1,1-dimethyl-3-prop-2-ynyloxy) derivatives of 7-hydroxy-8-methyl-3-phenyl-<4H>-1-benzopyran-4-one (1), 2,8-dimethyl-7-hydroxy-3-phenyl-<4H>-1-benzopyran-4-one (5), 8-(prop-2-enyl)-7-hydroxy-3-phenyl-<4H>-1-benzopyran-4-one (8), 8-(1-phenyl-2-propenyl)-7-hydroxy-3-phenyl-<4H>-1-benzopyran-4-one (11) was carried out to furnish novel products 1,2,3,7-tetrahydro-1,1,3-trimethyl-6-phenylcyclopenta-(2,3-h) <2H,7H>-benzopyran-2,7-dione (3), (7), and 2,2-dimethyl-7-phenyl-3(prop-2-enyl)pyrano (2,3-h) (8H)-1-benzopyran-8-one (10) along with expected products (4) and (13).Probable mechanisms of the rearrangements are discussed.