Base‐mediated cyclization of 3‐[2‐(2‐oxo‐2‐phenylethyl)‐1‐pyrrolidinyl]propanenitrile to 7‐phenyl‐1,2,3,7,8,8a‐hexahydroindolizine‐6‐carbonitrile: what lies between?

Garreth L. Morgans; Manuel A. Fernandes; Willem A. L. van Otterlo; Joseph P. Michael

Index: 10.1002/ejoc.201701714

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Abstract

Three intermediates along the reaction path by which 3‐[2‐(2‐oxo‐2‐phenylethyl)‐1‐pyrrolidinyl]propanenitrile is converted into the rel‐(7R,8aR)‐ and (7R,8aS)‐diastereoisomers of 7‐phenyl‐1,2,3,7,8,8a‐hexahydroindolizine‐6‐carbonitrile upon treatment with potassium tert‐butoxide were isolated and characterized. They include the rel‐(6R,7R,8aR)‐ and (6R,7S,8aS)‐diastereoisomers of 7‐hydroxy‐7‐phenyloctahydroindolizine‐6‐carbonitrile (the former obtained as a monohydrate), and 7‐phenyl‐1,2,3,5,8,8a‐hexahydroindolizine‐6‐carbonitrile. The alcohol intermediates and the final products were also characterized by X‐ray crystallography.