Mild Isomerative Opening of Tetrahydrofuranyl Subunits in Steroids Using TFAT (trifluoroacetyl trifluoromethanesulfonate): Application to Synthesis of C17-OH Rockogenin Acetate

Abstract

A novel and efficient tetrahydrofuranyl ring opening method was developed using the highly reactive TFAT reagent in the presence of an acid scavenger, 2,6-di-tert-butyl-4-methylpyridine. Various acid sensitive groups are compatible with the reaction condition, making it generally applicable to many tetrahydrofuranyl steroids. Moreover, it is a synthetic equivalent of 'Marker degradation' affording an efficient synthesis of C17-OH rockogenin acetate.