Ueber die Depolymerisierung von Poly-(R)-3-hydroxy-buttersaeureester (PHB)

Article abstract of DOI:10.1002/hlca.19820650208

On the Depolimerization of Poly-(R)-3-hydroxy-butanoate (PHB): From cell-free PHB or from dried cells of Alcaligens eutrophus H 16, which had been grown in an aqueous fructose solution, enantiomerically pure methyl, ethyl, butyl or β-methoxyethyl (R)-3-hydroxy-butanoates are obtained in yields ranging from 75-90percent (0.1 to 70 g scale).The depolimerization is achieved by heating the PHB-containing materials to temperatures of 80-100 deg C in the corresponding alcohol with or without the cosolvent dichloroethane in the presence of either sulfuric acid or tetraethoxytitanium catalyst.Since (S)-3-hydroxy-butanoates are also readily obtained (by yeast reduction of aceto-acetates), starting materials derived from 3-hydroxy-butyric acid now belong to the especially useful group of synthetic building blocks which are available in both enantiomeric forms.