3- Hydroxy propionic acid

Carboxylic Acids Obtained by Fermentation of Carbohydrates Lactic (2-hydroxy-propionic) acid obtained by fermentation of glucose and polysaccharides is used by NatureWorks (Cargill/Dow LLC) to prepare polylactide (PLA), a biodegradable or recyclable polymer with a potential production of 140000 t a-1 (Scheme 3.4) [23], This and other potential useful reactions from lactic acid have been reviewed by Datta and Henry [24],... 

Problem 34.15 Which specification, R or S, would you give to the following (a) D-(4 )-glyceraldehyde (b) D-(- )-glyceric acid (c) o-( >)-3-bromo-2-hydroxy-propionic acid (d) D-(-)-lactic acid. 

TSPtl Si02-15%Ta20s-3% Pt 2-Hydroxy-propionic acid... 

While many methods have been reported for the synthesis of chiral 2-hydroxy acids, few have proven to be reliable toward the synthesis of the title compound in terms of overall yield and enantioselectivity. Herein we describe a continuous enzymatic process for an efficient synthesis of (R)-3-(4-fTuorophenyl)-2-hydroxy propionic acid at a multi-kilogram scale with a high space-time yield (560 g/L/d) using a membrane reactor. The product was generated in excellent enantiomeric excess (ee>99.9%) and good overall yield (68-72%). This process can also be adapted to the synthesis of a variety of chiral 2-hydroxy acids with high yield and stereoselectivity. 

R)-3-(4-fluorophenyl)-2-hydroxy propionic acid 1 is a building block for the synthesis of Rupintrivir, a rhinovirus protease inhibitor currently in human clinical trials to treat the common cold (Fig. 1) [1, 2], Retrosynthetically, Rupintrivir was prepared from four fragments the lactam derivative Pi, the chiral 2-hydroxy acid P2 (compound 1), the valine derivative P3, and an isoxazole acid chloride P4 (Fig. 1). In this chapter the preparation of 1 using a biocatalytic reduction performed in a membrane reactor will be discussed in detail. 

An efficient and practical process has been described for the synthesis of (R)-3-(4-fluorophenyl)-2-hydroxy propionic acid at a multi-kilogram scale with good overall yields (68-72% for two steps), excellent stereoselectivity (>99.9% ee), and significant cost savings. The key to the process is the use of a continuous membrane reactor which was simple in concept, low cost in design, and provided high space-time yields. This method has a broad substrate spectrum in contrast to asymmetric chemical catalysis and a variety of chiral 2-hydroxy acids can be prepared. Moreover, by alternating d-LDH with l-LDH, both enantiomers can be synthesized. 

S)-2-hydroxy propionic acid (lactate)11321 and for the kinetic resolution of racemic 2-hydroxy acids[127, 131], but also for selective oxidations of 1,2-diols such as ethylene glycol (Fig. 16.2-30). 

The basic constitutional unit of PLA is lactic acid. Lactic acid (2-hydroxy propionic acid) is an a-hydroxy acid with an asymmetric carbon atom and exists either as L(-t-) or D(-) stereoisomer, as shown in Figure 8.1. 

Synonyms Acetonic acid Ethylidenelactic acid 1-Hydroxyethanecar-boxylic acid 1 -Hydroxyethane 1 -carboxylic acid 2-Hydroxypropanoic acid 2-Hydroxypropionic acid a-Hydroxypropionic acid Milk acid Propanoic acid, 2-hydroxy- Propionic acid, 2-hydroxy-Classification Organic acid... 

Hydroxypropionic acid a-Hydroxypropionic acid Milk acid Propanoic acid, 2-hydroxy- Propionic acid, 2-hydroxy-... 

The molecular structure of polylactic acid (PLA) is schematically presented in Fig. 2.2. PLA, linear aliphatic thermoplastic polyester, is prepared from lactic acid. Lactic acid (2-hydroxy propionic acid) is one of the simplest chiral molecitles and exists as two stereo isomers, L- and D-lactic acid (Fig. 2.3). 

Abstract PLA belongs to the family of aliphatic polyesters derived from a-hydroxy acids. The basic building block of PLA, lactic acid, (2-hydroxy propionic acid), can exist in optically active D- or L-enantiomers, which can be produced by carbohydrate fermentation or chemical syntihesis. Depending on the proportion of the enantiomers, PLA of with variable material properties can be derived. This allows the production of a wide spectrum of PLA polymers to match performance requirements. 

C4H8O3 2-hydroxy-propionic acid methyl ester 547-64-8... 

C5H10O3 2-hydroxy-propionic acid ethyl ester 97-64-3... 

CeHuOs 2-hydroxy-propionic acid propyl ester 616-09-1... 

C7H12O5 2-hydroxy-propionic acid 1-methoxycarbonyl-ethyl ester 2037-15-2... 

C7H14O3 2-hydroxy-propionic acid bntyl ester 138-22-7... 

CsHijClOs 2-hydroxy-propionic acid l-(2-chloro-ethoxycarbonyl)-ethyl ester ... 

C9H18O3 2-hydroxy-propionic acid hexyl ester 20279-51-0... 

CioHigOg 2-hydroxy-propionic acid 1-butoxycarbonyl-ethyl ester 13544-80-4... 

C14H26O5 2-hydroxy-propionic acid 1-octyloxycarbonyl-ethyl ester 5394-45-6... 

CisHsoOs 2-hydroxy-propionic acid dodecyl ester 6283-92-7... 

C17H34O3 2-hydroxy-propionic acid tetradecyl ester 1323-03-1... 

The basic ingredient of PLA is lactic acid, which is yielded from bacterial fermentation or from a petrochemical source. Lactic acid is a naturally occurring substance with the standard chemical name 2-hydroxy propionic acid. It is the simplest hydroxyl acid with an asymmetric carbon atom, and has optically active L(+) and D(—) isomers. Both L and D isomers are produced in bacterial systems, with the L isomer more commonly found. Meanwhile, mammalian systems produce only the L isomer, which is easily assimilated by enzyme protease K. Figure 4.2 shows the chemical structure of the L- and D-lactic acids. 

Lactic acid based polymer such as PLA belongs to the family of ahphatic polyesters. The PLA is formed by polycondensation of lactic acid (2-hydroxy propionic acid). It is a biodegradable polymer with a reasonable shelf life, for a wide variety of consumer products, such as paper coatings, films, moulded articles, and fiber applications (Datta et al., 1995). It degrades slowly by simple Itydrolysis of the ester bond to convert into harmless, natnral products like CO and H O (Drumright et al., 2000). 

Rhinovirus protease inhibitor enzymatic preparation of (A)-3-(4-fluorophenyl)-2-hydroxy propionic acid. 

---