A concise synthesis of (+/-)-cylindricine C and its C(13)-epimer is described. Starting from 1-octyne, cylindricine C and 13-epi-cylindricine C were prepared in 11% and 15% yields, respectively. The synthesis involves the preparation of the central tricyclic moiety via a radical alpha-iodoketone carboazidationibis-reductive amination sequence. Inversion of the stereochemistry at C(13) and C(5) was efficiently achieved on late stage intermediates.
Concise Synthesis of Pyrrolidine and Indolizidine Alkaloids by a Highly Convergent Three‐Component Reaction
作者:Guillaume Lapointe、Kurt Schenk、Philippe Renaud
DOI:10.1002/chem.201003137
日期:2011.3.7
The synthesis of pyrrolidine and indolizidine derivatives through radical carboazidation of alkenes with α‐iodoketones, followed by reductive amination, is described. When properly substituted, further lactamization afforded pyrrolizidinones in good yield. This carboazidation/reductive amination sequence was efficiently applied to the total synthesis of three different simple alkaloids, including (±)‐monomorine