In a recent development toward the synthesis of steroids, the intramolecular cycloaddition reaction has played an important role because of its effective regio-and stereoselectivity. Among the numerous reports using it as a key step, much attention has been focused on the synthesis of A-aromatic steroids1v2 such as estrone and estradiol and on the stereocontrolled construction of trans-hydrindan ring sy~ tems.~ We now report a novel ...
