[1]Fudan University Shanghai Medical College, School of Life Sciences and Institutes of Biomedical Sciences,Shanghai,China
[2]Fudan University, Department of Chemistry,Shanghai,China
[3]Northwest A&F University, College of Sciences,Yangling,China
The diastereoselective nucleophilic addition of organic boronic ester to 3-hydroxy-2-substituted N-acyliminium ions 9 led to the formation of 2,5-cis-pyrrolidine 10, from which a convenient synthesis of (-)-7a-epi-1 was developed. In addition, an efficient asymmetric synthesis of (-)-hyacinthacine A1 1 was achieved through the reduction/ring-opening process. © 2014 Elsevier Ltd. All rights reserved.