Abstract
Electrophile-induced cyclization of steroidal δ-alkenyl oximes and oxime ethers and subsequent hydride reduction of the cyclic nitrones led to new halogenated or selenylated N-hydroxy- or N-benzyloxy-aza-D-homo-estrones. Starting from a 13β-D-secoestrone oxime or oxime ether, steroidal dimers were isolated in intermolecular 1,3-dipolar cycloaddition of the cyclic nitrone to the C=N double bond of the oxazepine intermediates.
Keywords: Selenium, oxazepane, 1,3-dipolar cycloadditions, stereoselectivity, dimeric steroids, estrone derivatives