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A Novel Cyclopentene Annulation Method Based on Conjugate Addition Reactions of α‐Cyano Carbanion Species
Author(s) -
Tanino Keiji,
Tomata Yoshihide,
Shiina Yasuhiro,
Miyashita Masaaki
Publication year - 2006
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200500759
Subject(s) - chemistry , annulation , carbanion , cyclopentene , enone , acetic anhydride , conjugate , yield (engineering) , michael reaction , derivative (finance) , medicinal chemistry , enol , organic chemistry , catalysis , mathematical analysis , materials science , mathematics , economics , financial economics , metallurgy
A new cyclopentene annulation method based on a conjugate addition reaction with 4‐methoxybut‐3‐enenitrile was developed. Treatment of a cyclic enone with the potassium carbanion of the nitrile followed by acetic anhydride afforded an enol acetate, which underwent an HCl‐mediated intramolecular cyclization reaction to yield a bicyclo[ n .3.0]alkenone derivative in good yield. A lipase‐mediated optical resolution of the annulation product provided a new chiral building block for steroids and other natural compounds.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)