NEW DIASTEREOMERICALLY PURE AMINODIOL LIGANDS FROM (R)-(-)-PHENYLGLYCINOL AND CYCLOHEXENE OXIDE - SYNTHESIS AND CHARACTERIZATION OF THE LIGANDS AND OF THEIR DIOXOMOLYBDENYL COMPLEXES

The reaction of (R)-phenylglycinol with cyclohexene oxide at 100 degre es C gives a 1:1 mixture of the beta-aminodiols NH[(R)-cyclohexan-(R)- 2-ol][(R)-(R)-(R)-HNCyOH(2)] and H[(S)-cyclohexan-(S)-2-ol][(R)-(S)-(S )-HNCyOH(2)]. Recrystallization of the crude reaction product from hot toluene gave the (R)-(R)-(R) diastereomer in 33% yield. By addition o f petroleum ether to the filtrate, diastereomerically pure (R)-(S)-(S) -HNCyOH(2) was obtained in 12% yield. The aminodiol (R)-(R)-(R)-HNCyOH (2) has been methylated at nitrogen to give 3[(R)-cyclohexan-(R)-2-ol] [(R)-(R)-(R)-MNCyOH(2)]. The absolute configuration of all stereocente rs in the latter aminodiol has been determined by an X-ray diffraction analysis. H-1 NOESY spectroscopy has been used to determine the relat ive configuration at each stereocenter in the dioxomolybdenyl complexe s (R)-(R)-(R)-(R)-(HNCyO)MoO2 (1) and (R)-(R)-(R)-(R)-(MNCyO)MoO2 (2) in which a fourth asymmetric center is originated by the stereoselecti ve coordination of the nitrogen donor atom.