A series of yeasts were used in the bioreductions of aliphatic and aromatic γ- and δ-ketoacids and esters to investigate the preparation of enantiomerically pure γ- and δ-lactones through the intermediacy of their corresponding γ- and δ-hydroxyacids and esters. Bioreduction of ethyl 4-oxononanoate 2a with Pichia etchellsii afforded the γ-nonanolide (+)-5a with 99% e.e., while Pichia minuta proved to be the best choice for the bioreduction of ethyl 2-oxocyclohexylacetate 2e, which afforded cis-(-)-5e and trans-(-)-5e with 98 and 99% e.e., respectively. Reduction of 3-(2-oxocyclohexyl)propionic acid 3e with Pichia glucozyma gave predominantly the corresponding δ-lactone trans-(-)-6e with 94% e.e., whose absolute configuration was determined by means of CD spectroscopy.
Microbial bioreductions of γ- and δ-ketoacids and their esters / C. Forzato, R. Gandolfi, F. Molinari, P. Nitti, G. Pitacco, E. Valentin. - In: TETRAHEDRON-ASYMMETRY. - ISSN 0957-4166. - 12:7(2001), pp. 1039-1046. [10.1016/S0957-4166(01)00184-7]
Microbial bioreductions of γ- and δ-ketoacids and their esters
R. GandolfiSecondo
;F. Molinari;
2001
Abstract
A series of yeasts were used in the bioreductions of aliphatic and aromatic γ- and δ-ketoacids and esters to investigate the preparation of enantiomerically pure γ- and δ-lactones through the intermediacy of their corresponding γ- and δ-hydroxyacids and esters. Bioreduction of ethyl 4-oxononanoate 2a with Pichia etchellsii afforded the γ-nonanolide (+)-5a with 99% e.e., while Pichia minuta proved to be the best choice for the bioreduction of ethyl 2-oxocyclohexylacetate 2e, which afforded cis-(-)-5e and trans-(-)-5e with 98 and 99% e.e., respectively. Reduction of 3-(2-oxocyclohexyl)propionic acid 3e with Pichia glucozyma gave predominantly the corresponding δ-lactone trans-(-)-6e with 94% e.e., whose absolute configuration was determined by means of CD spectroscopy.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.