Facile transformation of 2-azetidinones to 2-piperidones: application to the synthesis of the indolizidine skeleton and (8S,8aS)-perhydro-8-indolizinol.
The highly functionalized bicyclic lactam 7 was prepared from diolefinic-2-piperidone 18 by the use of ruthenium-catalyzed RCM, and in turn, 18 was derived via a two-carbon addition process from readily accessible 4-olefinic-2-azetidinone 13. Bicyclic lactams 7 and 20 could serve as potentially valuable intermediates for the chiral synthesis of various hydroxylated indolizidine alkaloids as exemplified by the synthesis of (8S,8aS)-perhydro-8-indolizinol 19.
Lee
Hyeon Kyu
HK
Bio-Organic Science Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yusung, Taejon 305-606, Korea. leehk@krict.re.kr
Chun
Jong Soo
JS
Pak
Chwang Siek
CS