摘要:
(R)-2-Methyltryptopban ethyl ester, (R)-2, having an enantiomeric purity >,=96% was obtained in 3 steps and using (SSS)-hydroxypinanone, 1, as the recoverable chiral auxiliary. The synthesis of the alkylating agent, 5a, was improved (to a reproduceble 55% overall yield from 2,3-dimethylindole). The resolution of racemic-2 through chromatographic separation of the corresponding iminoester derived from (RRR)-1 also proved to be easy and efficient (similar to 25% yield). (C) 1998 Elsevier Science Ltd. All rights reserved.