(R)-3-Hydroxybutyric acid

(R)-3-Hydroxybutanoic acid is a metabolite, and converted from acetoacetic acid catalyzed by 3-hydroxybutyrate dehydrogenase. It is a monomer of PHB (poly[(R)-3-hydroxybutyrate]) with wide industrial and medical applications. It can also serve as chiral precursor for synthesis of pure biodegradable PHB and its copolyesters.

(R)-3-Hydroxybutyric acid may be used in the preparation of copolymers by reacting with various hydroxyalkanoic acids. It may also be used in the preparation of (3R,4R)-4-acetoxy-3-[(R)-1-(formyloxy)ethyl]-2-azetidinone.

ChEBI: (R)-3-hydroxybutyric acid is the R-enantiomer of 3-hydroxybutyric acid. Involved in the synthesis and degradation of ketone bodies, it can be used as an energy source by the brain during hypoglycaemia, and for the synthesis of biodegradable plastics. It is a sex pheremone in the European spider Linyphia triangularis. It has a role as a human metabolite, a pheromone and a fungal metabolite. It is a ketone body and a 3-hydroxybutyric acid. It is a conjugate acid of a (R)-3-hydroxybutyrate. It is an enantiomer of a (S)-3-hydroxybutyric acid.

Procedure for the Synthesis of (R)-3-Hydroxybutyric acid:Into a 50 ml flask was added 5N KOH (10 ml) which was cooled to 0 °C. Methyl [R]-3-Hydroxybutyrate (5 g) was then added with stirring over 1.5-h time period, and the temperature was maintained at 0 °C for 24 h. The reaction was terminated by the slow addition of 6N HC1 (8.3 ml) with stirring at 5 °C The resultant aqueous solution was then saturated with solid NaCl and extracted 20 times with 20 mL portions of diethyl ether. The organic extract was dried over anhydrous MgSO4 and the ether removed by rotary evaporation. The product was a white crystalline solid (3.8 g, yield 87%). NMR and IR were used to characterize the product.

Room temperature