TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The (3S,4R)-3-hydroxy-1-(4-methoxyphenyl)-4-phenylazetidin-2-one is prepared by lipase-enzyme catalyzed resolution for preparation of S-(+)-N,N-dimethyl-a-(2-(naphthalenyloxy)ethyl) benzenemethanamine. ACTIVITY - Antiinfertility.    MECHANISM OF ACTION - Serotonin reuptake inhibitor (SSRI). No biological data given.    EXAMPLE - A solution of benzaldehyde in dichloromethane was added 1.1 equivalent p-anisidine, and large excess of anhydrous magnesium sulfate and stirred at room temperature for 12 hours. The yellowish slurry was filtered and concentrated under reduced pressure and the crude imine (N-(4-methoxyphenyl)benzaldimine (A1)) was taken to the next step without purification (yield 90%). To the crude imine (A1) dissolved in anhydrous dichloromethane was added 3 equivalent of triethylamine and cooled to -78 degrees C. To this solution, 1.2 equivalents of acetoxyacetyl chloride were added dropwise and the thick reaction mixture was allowed slowly to warm-up to room temperature and stirred for 12 hours. After workup, ( plus minus )1-(p-metoxyphenyl)-3-acetoxy-4-phenyl azetidine-2-one (A2) was obtained. The racemic beta -lactam (A2) was then dissolved in acetonitrile and to this solution phosphate buffer at pH 7.2 was mixed and stirred vigorously. Immobilized Lipase PS Amano enzyme (one to one weight ratio to the lactam) was added and stirred for 2-3 days. The progress of the reaction was monitored by TLC, and after the completion of the reaction, the lipase was filtered off and the solution was worked-up in the usual way. After workup, polar, enantiomerically pure acetoxy- beta -lactam (48-50% yield based on the required isomer) was obtained. The solution of acetoxy- beta -lactam in tetrahydrofuran (THF) was added slowly to a 1 M KOH solution at 0 degrees C. The solution was stirred s45 min and the deacetylation reaction was completed. After workup, (3S,4R)-3-hydroxy-1-(4-methoxyphenyl)-4-phenylazetidin-2-one was obtained.