PNNL

Abstract

Glutamic acid provides a platform to numerous compounds through thermochemical approaches including, hydrogentation, cyclyization, decarboxylation and deamination. Hydrogenation of amino acids also provides access into chiral compounds with high enantio-purity. In this paper the hydrogenation of glutamic acid is examined with an emphasis on controlling the selectivity of carbonyl reduction. Under neutral conditions at 70 ºC, glutaminol is produced (US 6,310,254). At elevated temperatures pyroglutaminol is produced. Using base, the pyrrolidinone ring can be opened to give 4-amino-5-ol-pentanoic acid. Under acidic conditions, normally used for amino acids, the pyrrolidinone carbonyl is activated and prolinol is formed. A mechanism for the various products is suggested. The results show that hydrogenation of glutamic acid has unique characteristics from other amino acids and that paradigms in the literature do not hold up for this transformation.