Thiophene analogues of estrone; synthesis and structural assignment

Abstract

Abstract The synthesis of tetracycles of type 1 is described. Both la and lb are converted into the estrogen‐like compounds 12a and 12b via the corresponding α‐epoxides. The β‐epoxides yield mixtures of dienes. The stereochemical influence of the base on the alkene precursors for tetracyclic compounds, formed under Wittig‐Schlosser conditions, has been established. Finally, evidence is offered for the trans,anti,trans geometry in the tetracyclic molecules under discussion.