ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Simple Conversion of (R)-3-Hydroxybutanoic Acid to the (S)-Enantiomer and its Lactone (-)-(S)-4-Methylixetan-2-oneCondensation of (R)-3-hydroxybutanoic acid (1) with ethyl orthoacetate gives a 2-ethoxy-substituted (1,3)dioxanone 2 which is thermally labile: at ca. 100°, two competing processes commence, one leading to ethyl (R)-3-acetoxybutanoate (3), the other one - with complete inversion of configuration - to the (S)-4-methylixetan-2-one (4) and ethyl acetate. These can be readily separated by fractional distillation. Thus, enantiomerically pure (S)-3-hydroxybutanoic acid (ent-1) and l-2-alkyl-3-hydroxybutanoic-acid derivatives (such as 6 and 8) become available from the biopolymer PHB, the precursor to the acid 1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19870700513
