Enzymatic Racemic Resolution of a Fluorinated Substrate and Syntheses of E and Z Alkenes as Precursors for Some Biologically Active Fluorohexoses

M u h a m m a d S h a iq A li* a, T o m o y a K ita z u m e b, V iq a r U d d in A h m a d 3 a H. E. J. R esearch Institute of Chemistry, U niversity of Karachi, Karachi-75270, Pakistan b D epartm ent of Bioengineering, Faculty of Biosciences & Biotechnology, Tokyo Institute of Technolgy, 4259 N agatsuta-cho, M idori-ku, Y okoham a 227, Japan Z. N aturforsch. 52b, 413-418 (1997); received D ecem ber 9, 1996 Fluorinated Substrate, Enzym atic Racem ic R esolution, A lkenes A fluorinated substrate 6 was p repared and then the enantiom ers (6a and 7a) were sepa­ rated by an enzyme in presence of an acetylating agent. The optical purity of 6a and 7a w ere determ ined by derivatising them into their M TPA -esters and then by taking their 19F NM R spectra. It was observed that, PL 266 (enzym e), benzene (solvent), 24 h (tim e), 40 °C (temp.) and vinyl acetate (acetylating agent) w ere the ideal conditions for racemic resolution. The optical purity was further im proved by changing the solvent (hexane), am ount of enzyme (PL 266; 3000 units), reaction time (12 h) and am ount of acetylating agent (vinyl acetate; two m olar). The optically pure species was used for the p reparation of E and Z alkenes.