Lactic acid esters

In addition to solvent uses, esters of lactic acid can be used to recover pure lactic acid via hydrolysis, which in-tum is used to make optically active dilactide and subsequently polylactic acid used for drag delivery system.5 This method of recovery for certain lactic acid applications is critical in synthesis of medicinal grade polymer because only optically active polymers with low Tg are useful for drug delivery systems. Lactic acid esters themselves can also be directly converted into polymers, (Figure 1), although the commercial route proceeds via ring-opening polymerization of dilactide. 

Methyl pyruvate has been prepared from the silver salt of pyruvic acid and methyl iodide,3 and from the free acid by the alcohol-vapor method without a catalyst.4 Pyruvic esters have also been prepared by the dehydrogenation of lactic acid esters.5... 

Especially high optical inductions have been achieved with catalysts which contain BPPM (13), PPM (14) or (15) as chiral ligands. Pyruvic acid esters were usually hydrogenated to lactic acid esters in quantitative chemical yield with an enantiomeric excess of 65-75%41 a,53). However, this method is not of technical significance, since chiral lactic acid derivatives may be produced more conveniently by biotechnological processes. 

Lactic acid esters of mono- and diglycerides Acetylated or none tartaric acid esters of mono- and diglycerides (DATEM)... 

L. A., Dremova, V. P., and Markina, V. V., Repellent effect of Mannich bases derived from lactic acid esters, Med. Parazilol. Par-azil. Bolezni. 44, 1987 Chem. Ahsir, 107, 192961. 1987. 

PGE Polyglycerol Esters of fatty acids DATEM Diacetyl Tartaric Esters of Mono-digiycerides GLP Glycerol Lacto Palmitate (Lactic acid esters)... 

Lactic acid esters Na stearoyl-2-lactoyl lactate 21... 

LACTIC ACID ESTERS (METHYL AND ISOBUTYL ESTERS)... 

GC on cyclodextrine type CSP of the O-TFA derivative of the lactic acid ester Acceptable resolution between the two enantiomers Good reproducibility of the method Requires double derivatization Unknown column stability over time < 0.3 %... 

The stationary phase used is specially prepared for the analysis of lactic acid ester enantiomers. Indeed, conventional commercial CSP s contain D-phenyl glycine. With this type of substrate, the "L" enantiomers are eluted after the "D enantiomers. Because of this, the detection limits of the "L" enantiomer in the "D" enantiomer are greater than 1 %. 

Imwitor . [HQls Am. HQls AG] Glyceryl derivs., propylene glycol, tartaric, citric, or lactic acid esters emulsifier, disposant, suspending agent, stabilizer, thideener for food, personal care prods., pharmaceuticals, lubricants. 

L-( + )-Lactic acid (1), the naturally occurring form, is commercially available from a large number of suppliers, and is inexpensive. At this writing, the price of 1 kg is less than 60. Although 1 may be esterified with an alkyl iodide in the presence of CsF [1], carrying out this process is unnecessary since many lactic acid esters are commercially available, and some are even less expensive then the parent acid. For example, 500 g of ethyl ( S)-( — )-lactate (2) can be purchased for less than 14. 

Tosyl lactates 120 are readily prepared by treating the corresponding L-lactic acid ester with />-toluenesulfonyl chloride in the presence of either pyridine [45] or triethylamine [30]. Ethyl ester 120b has been prepared on a multi-kilogram scale in nearly 97% yield [46]. Careful hydrolysis of the ester furnishes ( S)-( — )-2-tosyloxypropionic acid 121. 

Benzylation of lactic acid esters can be accomplished by two methods. Treatment of methyl or ethyl L-lactate with benzyl bromide and silver oxide provides the corresponding (5)-2-ben-zyloxypropionates 271 with high optical purity [92,93]. Use of standard basic conditions (NaH, DMF) results in considerable racemization (50-75% ee). 

H.R. AUcock, S.R. Pucher, A.G. Scopelianos, Synthesis of poly(orgnaophosphazenes) with glycolic acid ester and lactic acid ester side groups prototypes for new bioerodible polymers, Macromolecules 27 (1) (1994) 1-4. 

In addition, EC formulations were prepared using a few proprietary experimental herbicides, belonging to the protoporphyrinogen oxidase (PPO) inhibitors (Figure 10.7). Several safer solvents were tested and most formulations resulted in a generally increased efficacy, but only a select number of long-chained lactic acid esters were found to provide a significantly increased selectivity toward crops. 

Chem. Descrip. Lactic acid ester of mono-diglyceride from edible refined hydrogenated vegetable fat... 

These halogenated solvents, especially chloroform, pose a high risk not only to the environment, but also to the personnel working with them. In order to avoid leaving the patterns of sustainability in biopolymer production, it will be indispensable to concentrate the development of new extraction processes on such recyclable solvents that are also of an environmentally benign nature, such as lactic acid esters [73]. 

Axoi E 66. See Acetylated mono- and diglycerides of fatty acids Axoi L 626. See Lactic acid esters of mono-and diglycerides of fatty acids Axole. SeeFuran... 

Definition Lactic acid ester of glyceryl palmitate Empirical C22H42O6 Properties Nonionic... 

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