PREPARATIVE SEPARATION AND PROPERTIES OF (E)-STEROIDAL AND (Z)-STEROIDAL ALPHA,BETA-UNSATURATED KETOXIMES

A procedure for the preparative resolution of (E)- and (Z)-norgestimat e ta-acetyloxy-13-ethyl-18,19-dinorpregn-4-en-20-yne 3-oxime) using fl ash chromatography is described. A longer column and less polar solven ts were applied to overcome the small DELTAR(F)(0.05) for the isomers of norgestimate. The optical rotations of the E and Z isomers were +4. 7-degrees and +94.7-degrees (in CHCl3), respectively. The E/Z isomer r atio in the mixture was found to be 1.5 both by H-1 NMR spectrometry ( 4-olefinic H peaks) and by measurement of optical rotations. The valid ity of the above two methods was confirmed by the calibration graphs o btained with the resolved isomers. The properties of the resolved isom ers are discussed with a comparison with those for testosterone oxime.