Steroids, XXXVIII. Neighbouring group participation, IX. Preparation of 16α-hydroxymethyl-3-methoxyestra-1,3,5(10)-trien-17α-ol and solvolysis investigations

✍ Scribed by Schneider, Gyula ;Hackler, László ;Sohár, Pál

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 575 KB
• Volume: 1988
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.198819880711

✦ Synopsis

Solvolysis of the p-toluencsulfonate Id in acetic acid and in dinicthyl sulfoxide yields 5b with inversion at C-17. The conversion can be explained by a neighbouring group participation characterized by the general symbol (Ad-6). In order to confirm the participation of the 16a-acetoxymethyl group in Id, comparative solvolytic invesligations were carried OUI with the toluenesulfonate 9.

A previous paper1) reported that the reduction of 16-acetoxymethylene-3-methoxyestra-l,3,5(10)-trien-17-one with NaBH4 in alcohol yielded a mixture of 16a-and 16P-hy-

3 b Ac H Ts OR H3C0 , * H2 ( j 3 / L H 2 OR , * \ . , HZ CH, yR 6 Steroide, XXXYm ''. -Nacbbargruppen-Beteiligung, I X '). -Syntbese von 16a-HydroxymethyE3-methoxyestra-lJ,Y 10)trieo-17a-01 und Solvolyse-Untersuchungen Solvolyse des pToluolsuUonats I d in Essigslure und in Dirncthylsulfoxid iiehrt 5b unter Inversion der Konliguration an C-17. Die Umsetzung IN31 sich durch Nachbargruppen-Beteiligung [allgerneines Symbol (Ac0-6)] erkllren. Zur Bestgtigung der Nachbargruppen-Beteiligung der 16a-Acetoxyrnethyl-Gruppe wurden Vergleichsuntersuchugen rnit .l-Methoxy-l7~-p-tolylsulfonyloxyestra-l,3,5( lO)-trien (9) durchgefiihrt.