N-arylurethane neighboring group participation during solvolysis of 3-methoxy-17-N-phenylcarbamoyloxy-16-p_tolylsulfonyloxymethylestra-1,3,5(10)-triene stereoisomers

✍ Scribed by László Hackler; Gyula Schneider; Pál Sohár

• Book ID: 104203406
• Publisher: Elsevier Science
• Year: 1992
• Tongue: French
• Weight: 599 KB
• Volume: 48
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(01)85620-9

✦ Synopsis

During alkaline methanolysis of the four stereoisomers l-4 of 3methoxy-17-~phenylcarbamoyloxy-l6-~tolylsulfonylox~ethylestra-l,3,5~10~-triene, a cyclization takes place, in the course of which the Wphenyltetrahydrooxazin-a-one derivatives 5-S are formed. The cis isomers 5, 8 and 8a-e are thermodynamically stable endproducts, while the tram derivatives 6 and 7, formed in a kinetically controlled process, undergo ring cleavage on methanolysis to yield the 16-(Wphenyl,N-methoxycarbonylaminomethyl) derivatives 9 and 11. The cyclization takes place with (N--6) neighboring group participation.