We show a convenient decarboxylative aldol process using a scandium catalyst and a PYBOX ligand to generate a series of highly functionalized chiral α-hydroxy esters. The protocol tolerates a broad range of β-keto acids with inactivated aromatic and aliphatic α-keto esters. The possible mechanism is rationalized.

A facile synthetic route towards pharmaceutically interesting β-keto-sulfone derivatives by tetrabutylammonium iodide (TBAI)/tert-butyl hydroperoxide (TBHP) mediated oxidative coupling of readily prepared enamides with economical sulfonylhydrazides is described. The corresponding β-keto-sulfone compounds were obtained in moderate to good yields. The present method is metal-free and base-free an...

The direct chiral Lewis acidic enantioselective chlorination and fluorination of beta-keto phosphonates is presented; the chlorination proceeds in high yields and with up to 94% ee using NCS as the chloro source, while the fluorination with (PhSO2)2NF (NFSI) gives the optically active alpha-fluoro-beta-keto phosphonates in moderate to good yields and with up to 91% ee.

The tumor promoters, 12-O-tetradecanoylphorbol-IS-acetate (TPA), phorbol-12,13-didecanoate, teleocidin, and dihydroteleocidin, at nw levels, but not the non-tumor-promoting 4«-phorbol12,13-didecanoate even at ¡Mconcentrations, stimulated arachidonic acid metabolism in cultured rat liver cells. These liver cells synthesize primarily prostaglandin I2 [measured as its nonenzymatic hydrolytic pro...

The renal vascular effects of prostaglandin E2 (PGE2), 6-keto-PGE1, and PGI2 were investigated in indomethacin-pretreated rats. These prostanoids were infused directly into the left renal artery at rates ranging from 0.01 to 1.0 microgram/min, while renal blood flow and mean arterial blood pressure were constantly monitored. PGE2, 6-keto-PGE1, and PGI2 produced reductions in mean arterial blood...

Prostaglandin release from microvessels isolated from the rabbit cerebral cortex was determined under three different atmospheric conditions: 100% O2 ("O2") room air, and 95% N2:5% CO2 ("N2-CO2"). Initial studies with homogenates prepared from rabbit cerebral microvessels (RCMV) indicated two pathways of enzymatic PGH2 transformation, namely PGI2 synthase and GSH-dependent PGH-PGE isomerase. We...

Metabolism of aromatic amino acids by lactic acid bacteria is an important source of off-flavor compounds in Cheddar cheese. Previous work has shown that alpha-keto acids produced from Trp, Tyr, and Phe by aminotransferase enzymes are chemically labile and may degrade spontaneously into a variety of off-flavor compounds. However, dairy lactobacilli can convert unstable alpha-keto acids to more-...

Excretion of alpha-keto acids by clinical isolates and laboratory strains of Salmonella typhimurium was determined by high-performance liquid chromatography analysis of culture supernatants. The levels of excretion increased markedly with increasing iron stress imposed by the presence of alpha,alpha'-dipyridyl or conalbumin in the medium. The major product was pyruvic acid, but significant conc...