Diastereoselective Zwitterionic Aza-Claisen Rearrangement: The Synthesis of Bicyclic Tetrahydrofurans and a Total Synthesis of (+)-Dihydrocanadensolide
作者:Udo Nubbemeyer
DOI:10.1021/jo9600464
日期:1996.1.1
The zwitterionic Claisen rearrangement of optically-active N-allyl pyrrolidines and various acid chlorides proceeds with high simple diastereoselection (internal asymmetric induction) and high 1,2-asymmetric induction, generating a new C-C bond adjacent to a chiral C-O function. The resulting gamma,delta-unsaturated amides were cyclized to the corresponding optically active gamma-butyrolactones, which
光学活性N-烯丙基吡咯烷和各种酰氯的两性离子Claisen重排伴随着高简单的非对映选择性(内部不对称诱导)和高1,2-不对称诱导,产生了与手性CO功能相邻的新CC键。将所得的γ-δ-不饱和酰胺环化为相应的旋光性γ-丁内酯,其是天然产物合成中有用的中间体。一方面,几种内酯的非对映选择性碘环化反应产生了四氢呋喃,其取代模式代表了氧杂-前列腺素合成的关键中间体。另一方面,一锅法的Swern氧化和一个γ-内酯的连续格氏反应使非对映选择性链延长。