The intermolecular [3+ 2] annulation of azomethine ylides with 2 (2-nitrophenyl) acrylate dienophiles followed by reductive heterocyclization affords the spiro (indole-pyrrolidine) ring system. Hence, this enable us to accomplish a concise and highly enantioselective synthesis of (-)-horsfiline 1, based on chiral auxiliary-directed π-face discrimination in the 1, 3-dipolar cycloaddition of (1 S, 2 R)-2-phenyl-1-cyclohexyl ester 4f with N- ...
