New ring-expansion reactions of hydroxy propenoyl cyclic compounds under palladium(0)/phosphine-catalyzed conditions
Palladium(0)-catalyzed one-atom ring-expansion of 1-hydroxy-2,2-dialkyl-1- propenoylindan derivatives has been achieved in the presence of P(o-tolyl) 3 giving 2-hydroxy-3,3-dialkyl-2-vinyl-1-tetralone derivatives in excellent yields. This ring-expansion reaction was applied to a 17-(1-oxo-2-propenyl)-β-estradiol derivative and furnished a similar ring-expanded product in an excellent yield.