[34] Preparation of d(−)-3-phosphoglyceric acid

This chapter discusses the preparation of 3-phosphoglyceric acid (3-PGA). 3-phosphoglyceric acid (3-PGA) may be prepared by three different methods. It may be prepared biologically from yeast and sugar phosphate solution in the presence of acetaldehyde or another hydrogen acceptor and fluoride. The method discussed in this chapter has advantages of using commercial Baker's yeast instead of the more difficultly available washed and pressed bottom yeast. Racemic 2-PGA prepared from Na β-glycerophosphate can be converted by muscle extract to D(-)-3-PGA, which can be isolated in pure form, owing to the low solubility of the Ba salt of PGA compared to that of 2-PGA. Total synthesis has been accomplished from free D-glyceric acid and metaphosphoric acid ester by an adaptation of the method originally devised for the racemic compound. D(-)-3-PGA is the main product and is separated as the acid Ba salt from the D(+)-2-PGA formed at the same time.