Delta lactones

Reaction between butadiene and CO2 has been extensively studied (171) since the reaction was first demonstrated (167—170). This reaction has been shown to be catalyzed by Pd (172,173), Ni (174), Ru (175), Pt (178), and Rh (172,173) catalysts. Products include gamma (5) and delta lactones (6), acids (7,8), and esters (9). Mechanistic studies have shown that butadiene initially forms a dimer (Pd, Ru, Ni) or trimer (Rh) intermediate followed by CO2 insertion (171). The fate of these intermediates depends on the metal, the ligands, and the reaction conditions. 

The delta lactone can be obtained in very high yields when triisopropylphosphine or tricyclohexylphosphine is the ligand along with Pd(acac)2 as the metal source (171). 

Precipitation of Fe(IIl) compounds from acid solutions as the pH increases above 2.2 is a particular problem. Complexing agents that have been used include 5-sulfosalicylic acid and citric acid (136) dihydroxymaleic acid (137) ethylenediaminetetraacetic acid (138) lactic acid (138) blends of hydroxylamine hydrochloride, citric acid, and glucono-delta-lactone (139) nitriloacetic acid blends of citric acid and acetic acid lactic acid and gluconic acid (140). 

Contains one or more optioned acidifying ingredients adipic acid, citric acid, fumaric acid, glucono-delta lactone, hydrochloric acid, lactic acid, malic acid, phosphoric acid, succinic acid, and tartaric acid. 

Calcium chloride Calcium citrate Calcium gluconate Calcium phosphate, monobasic Citric acid Disodium EDTA Glucono delta-lactone Oxystearin Phosphoric acid Potassium citrate... 

Lucey, J.A., Tamehana, M., Singh, H., and Munro, P.A. 1998. A comparison of the formation, rheological properties and microstructure of acid skim milk gels made with a bacterial culture or glucono-delta-lactone. Food Res. Imernatl. 31 147-155. 

A model wheat bread was prepared by a straight dough procedure from wheat flour, salt and water using glucono-delta-lactone as leavening agent (Schieberle, P., in preparation). The bread crust showed an odor note reminiscent of day-old bread and, specifically the cracker-like, roast odor note was lacking. 

A dough prepared from 500 g wheat flour (type 550), 12 g glucono-delta-lactone, 10 g salt and ca. 270 ml of tap water was baked for 30 min at 220°C. 

Glucono Delta-Lactone occurs as a fine, white, crystalline powder. It is freely soluble in water and is sparingly soluble in alcohol. It decomposes at about 153°. 

Glucono- Delta- Lactone Lactic Acid Malic Acid Phosphoric Acid Tartaric Acid... 

Aldonic acids are in equilibrium with their lactones, formed by reversible esterification of the carboxyl group with a hydroxyl in 4 or 5 position (gamma and delta lactones) (e.g. delta-gluconolactone Fig. 7.6). 

Another Important attribute of whole cell/enzyme systems is for the production of optlcally-actlve compounds. As early as the 1950s, the synthesis of optically active gamma- and delta-lactones by microbiological reduction was demonstrated (18). Production of optlcally-pure L-glutamate for use in the flavor enhancer MSG by microbial means is another testimonial to this potential of biotechnology. 

C6H10O2 b-methyl-D-valerol actone 10603-03-9 435.22 37.696 2 7957 C6H10O6 delta-lactone-D-gluconic acid 90-80-2 553.15 49.014 2... 

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