α-Ketol rearrangements involving small rings: the formation and rearrangement of 1-hydroxy-6-isopropylbicyclo[3.2.0]heptan-7-one

Abstract

1-Hydroxy-6-isopropylbicyclo[3.2.0]heptan-7-one (2) is formed by ciné-substitution of the corresponding 6-exo-chlorobicycloheptan-7-one (1), and is shown to be in equilibrium with 1-hydroxy-7-isopropylbicyclo[4.1.0]-heptan-2-one (3) by basic catalysis; ¹⁴C-tracer studies show that 1-hydroxy-7-isopropylbicyclo[3.1.1]heptan-6-one (4) is to a lesser extent involved in the α-ketol rearrangements.