Regio- and stereo-controlled oxygen functionalization of cholesterol by photooxygenation in the presence of titanium tetraisopropoxide

✍ Scribed by Adam, Waldemar ;Staab, Eugen

• Book ID: 102364188
• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 321 KB
• Volume: 1988
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.198819880809

✦ Synopsis

A convciiicnt "onc-pot" proccdurc for thc synthesis of thc cpoxy alcohols Ic and 2c by photooxygenation of cliolcstcrol (1) in thc presence of Ti(OiPr14 was developed. Thc reaction proceeds rcgioscleciively and stereospecifically. During the photooxygena- iicm or 1 in thc prcsencc of Ti(1V) oxygen transfcr l a + Ic takes place much fastcr than ihc radical promoted isomerization la-+2a, thcrchy providing for rcgio-control. In contrast to fHuOOH,llri(OiPrl, cpoxidations of the allylic alcohols 1 b and 2b. derived from the reduction of the allylic hydropcroxidcs l a and 221, n o furihcr oxidaiion products. c.g. the keto cpoxy alcohol Id, were ohsorvcd undcr the "one-pot" conditions.