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Pyroglutamic Acid in Drug Synthesis, Part 1 A Method for the Synthesis of Enantiomerically Pure 4-Alkyl-4-arylpyroglutamic Acids

✍ Scribed by Wilhelm Fleischhacker; Thomas Riedl; Horst Völlenkle; Christian R. Noe

Publisher: John Wiley and Sons
Year: 1996
Tongue: English
Weight: 871 KB
Volume: 329
Category: Article
ISSN: 0365-6233
DOI: 10.1002/ardp.19963290108

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✦ Synopsis

Synthesis of the title compounds is described, starting from alkylation of the pyroglutaminol-acetal 4a"' at the a-lactam position C-6 with methyl iodide. Subsequent addition of 2-cyclohexen-lone led to diastereoselective formation of the 1.2-aldol addition product 7 W c , which after dehydratization was aromatizrd with DDQ to yield the 6-methyl-6-phenyl derivative 7h. Acetal cleavage and Jones oxidation yielded 4,4-disubstituted. enantiomerically pure pyroglutamic acid 3b. X-ray analysis confirmed the assignment of the configuration of the newly created chiral centre.

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