Approach to chiral vicinal diacylamines by Bamberger ring cleavage of substituted imidazoles

✍ Scribed by Altman, Janina ;Grinberg, Mircea ;Wilchek, Meir

• Book ID: 102367104
• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 477 KB
• Volume: 1990
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199019900164

✦ Synopsis

Abstract

Ring cleavage of ethyl 3‐[4(5)‐imidazolyl]propanoate (1) with (−)‐menthyl chloroformate introduces chiral carbamate substituents on the double bond which, upon hydrogenation, induces preferred formation of ethyl (4__S__)‐4,5‐bis[(−)‐menthyl‐oxycarbonylamino]pentanoate (5) (5:1 ratio of diastereomers). The ring cleavage benzoylation product of (S)‐histidine methyl ester, with a chiral center in the side chain, gives rise to (2__S__,4__R__)/(2__S__,4__S__)‐2,4,5‐tribenzamidopentanoates (13, 14), in 2:1 ratio upon hydrogenation.