5335. d-Lactic Acid

Nomenclature

CAS number: 10326-41-7
(2R)-2-Hydroxypropanoic acid; d()-lactic acid; (R)-()-lactic acid; levorotatory lactic acid; l-lactic acid; d-Milchsure (German).
C3H6O3; mol wt 90.08.
C 40.00%, H 6.71%, O 53.28%.

Description and references

Obtained by resolution of dl-lactic acid: Purdie, Walker, J. Chem. Soc. 61, 754 (1892); Borsook et al., J. Biol. Chem. 102, 449 (1933). Convenient laboratory prepn from glucose using Lactobacillus leichmannii: Brin, Biochem. Prep. 3, 61 (1953).

Chemical structure

Properties

Crystals from ether + isopropyl ether, mp 52.8°. [α]54621.5 2.6° (c = 8). pK = 3.83. Sol in water, alcohol, acetone, ether, glycerol. Practically insol in chloroform. Forms salts with many metals. Most of these salts are dextrorotatory.

Derivative

Zinc d(+)-lactate dihydrate.
Zn(C3H5O3)2.2H2O; mol wt 279.58.
Zn 23.40%, C 25.78%, H 5.05%, O 45.78%.

Properties

Crystals, [α]D14 +8.18° (c = 2.5).