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Esterification of Maleamic Acids without Double Bond Isomerization
Author(s) -
Sánchez Albert,
Pedroso Enrique,
Grandas Anna
Publication year - 2010
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.200901365
Subject(s) - chemistry , isomerization , alcohol , pyridine , diastereomer , chloride , medicinal chemistry , double bond , organic chemistry , acyl chloride , carboxylic acid , picoline , catalysis
Activation of the carboxylic acid group of a maleamic acid by treatment with an arenesulfonyl chloride followed by addition of an alcohol affords a fumaramate or a maleamate, depending on the reaction conditions. The E isomer is obtained when the acid is treated with nearly equimolar amounts of 2,4,6‐triisopropylbenzenesulfonyl chloride and an alcohol in pyridine. Replacement of pyridine by 2‐picoline and use of a larger excess of activating agent (mesitylenesulfonyl chloride) and alcohol affords the Z isomer. In both cases, high diastereomeric excesses and yields are achieved.