Reference

Lipase-catalyzed production of optically active acids via asymmetric hydrolysis of esters

Lipase-catalyzed production of optically active acids via asymmetric hydrolysis of esters. Effect of the alcohol moiety. Cambou, Bernard; Klibanov, Alexander M. (Dep. Nutr. Food Sci., Massachusetts Inst. Technol., Cambridge, MA 02139, USA). Appl. Biochem. Biotechnol., 9(3), 255-60 (English) 1984. CODEN: ABIBDL. ISSN: 0273-2289. DOCUMENT TYPE: Journal CA Section: 16 (Fermentation and Bioindustrial Chemistry) Lipase [9001-62-1] from Candida cylindracea hydrolyzed octyl R(+)- [92484-25-8] but not octyl S(-)-2-chloropropionate [92484-24-7]. The enzyme exhibited no appreciable stereoselectivity in the hydrolysis of the Me ester of the same acid. Soly. detn. expts. showed that Me 2-chloropropionate [17639-93-9] was completely dissolved in H2O, whereas the octyl ester existed as an emulsion in H2O. Apparently, lipase needs to adsorb on the substrate-H2O interface in order to express its stereoselectivity. R,S-2-Chloropropionic acid [62138-52-7] was preparatively resolved by yeast lipase-catalyzed asym. hydrolysis of its octyl ester. Gram quantities of R(+)-2-chloropropionic acid [7474-05-7] and octyl S(-)-2-chloropropionate of high optical purity were readily prepd.

Racemization of optically active chlorocarboxylic acids

Racemization of optically active chlorocarboxylic acids. Siuta-Mangano, Patricia; Dahod, Samun K. (Stauffer Chemical Co., USA). U.S. US 4613689 A 23 Sep 1986, 4 pp. (United States of America) CODEN: USXXAM. CLASS: ICM: C07B055-00. NCL: 562401000. APPLICATION: US 85-771091 30 Aug 1985. DOCUMENT TYPE: Patent CA Section: 23 (Aliphatic Compounds) Optically active R1R2ClCRnCOOH (I; R = aliph., arom.; R1, R2 = H, alkyl; R1 1 R2; n = 0, 1) were racemized in aq. 7474-05-7 and 40705-03-1 are also in the experiment. HCl. D-2-Chloropropionic acid [obtained from the enzymic resoln. of D,L-methyl2-chloropropionate (+4.787°)] was racemized in 6 N HCl to give the isomeric mixt. which exhibited an optical rotation of +0.050°. .