Acid-catalysed skeletal rearrangement of an epoxy derivative of terrecyclic acid A. Formation of a 5-oxatetracyclo[5.5.1.04,13.010,13]tridecane derivative

Abstract

Treatment of the epoxide 3 which is derived from a sesquiterpene antitumour antibiotic, terrecyclic acid A 1, with BF₃·OEt₂ in benzene, affords a skeletally rearranged ether 6 as the sole product; its structure was deduced from spectroscopic data including, 2D NMR data, to be [1S, 2S, 4R, 7R, 10S, 13R]-2-hydroxy-11,11-dimethyl-5-oxatetracyclo[5.5.1.0^4,13.0^10,13]tridecan-1-ylmethanol.