Homocitric acid

A.T. Russell and co-workers synthesized (R)-(-)-homocitric acid-y-lactone in multigram quantities starting from a citric acid derivative and using the Amdt-Eistert homologation as the key step. ... 

Anciiff, R. A., Russeii, A. T., Sanderson, A. J. Resoiution of a citric acid derivative synthesis of (R)-(-)-homocitric acid-y-iactone. 

A similar reaction is catalyzed by homoaconitate hydratase (E.C. 4.2.1.36), which is an enzyme from the L-lysine synthesis that forms homocitric acid (2-hydrox-ybutane-l,2,4-tricarboxylic acid, 17) from homo-ris-aconitate (16)The enzyme 2-methylcitrate dehydratase (E. C. 4.2.1.79) catalyzes the addition of water to (Z)-but-2-ene-l,2,3-tricarboxylic acid (18) to yield 2-methylcitric acid (2-hydroxybutane-... 

Intermediate 954 can also be used to synthesize (— )-homocitric acid (958). Only a modification in oxidation of the acetylene moiety is required. In the synthesis of 955, oxidation of... 

The accumulation of -carboxy- -hydroxyadipic acid (homocitric acid) in the culture medium of the lysine-requiring yeast mutant, Ly4, grown on limiting amounts of lysine, has been demonstrated by Maragoudakis and Strassman (1966). Infrared spectra were used to affirm identification of the biologically formed acid, as were Ry s, optical rotations, and melting points. 

After weighing the different posibilities to counter the lack of equal labeling in carbons 3 and 6 of lysine, Strassman and Weinhouse 180) propose as the more likely synthetic mechanism, a condensation of an acetyl methyl carbon with the carbonyl carbon of a-ketoglutarate, similar to the condensation of acetyl CoA and oxalacetate to yield citrate. This reaction would form homocitric acid. Upon oxidation and decarboxylation of the latter there would be obtained a-ketoadipic acid. Transamination of a-ketoadipic acid produces a-aminoadipic acid, which can be converted to lysine by reduction to the corresponding semialdehyde, followed by transamination. 

Conjugate addition of nitroalkanes to a,P-unsaturated aldehydes in the presence of imidazolyl-imidazolidin-4-ones was described by Arvidsson and coworkers [92], In addition, silyl enol ethers of substituted acetophenones [93] or thioesters [94] react with a,P-unsaturated aldehydes under iminium-catalysis conditions in the sense of a Mukaiyama-Michael reaction (Scheme 4.24). Applications of this transformation can be found in the total syntheses of compactin [95] and homocitric acid lactone and its homolog [96]. 

Homaline, K30 Homocamphor, T27 Homocaronic acids, A35 Homochasmanine, K9 Homochrysanthemic acids, A3 5 Homocitric acid, A26 Homoerythrina alkaloids, K7 Homolycorine, K6 Homopterocarpin, Y3 Homosecodaphniphyllic acid, methyl ester, K26... 

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