De. Hibbs et al., PREPARATION AND DETERMINATION OF THE ABSOLUTE-CONFIGURATION OF OPTICALLY-ACTIVE 9-HYDROXY-7-OXABICYCLO[4.3.0]NON-4-EN-8-ONES, Acta chemica Scandinavica, 49(2), 1995, pp. 122-127
Both enantiomers of endo-9-hydroxy-7-oxabicyclo[4.3.0]non-4-en-8-one (
+)-(3) and(-)-(3) as well as 1R,6R,9R)-9-hydroxy-7-oxabicyclo[4.3.0]no
n-4-en-8- one (+)-(4) have been obtained in states of high optical pur
ity by kinetic resolutions involving enzyme-catalysed hydrolyses. Abso
lute configurations were assigned by chemical interconversions and by
X-ray crystallography on Mosher's ester(+)-(7).