(3-bromo-4,5-dihydro-1,2-oxazol-5-yl)methanamine

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of N-benzyloxycarbonyl-L-phenylalanine, 0.84 gm, at -20° C. in 50 ml of dry CHCl3, was added N-methyl piperidine, 0.34 ml, with stirring under argon. After 5 minutes, isobutyl chloroformate, 0.36 ml, was added dropwise and after 20 minutes, 5-aminomethyl-3-bromo-4,5-dihydroisoxazole, [optically active [α]D23 =+208.6 (CH2Cl2)] 0.5 gm, was added dropwise in 10 ml of dry CHCl3. One hour after the addition, the reaction mixture was brought to room temperature and three hours later, the reaction mixture was washed with 20 ml each of 5% HCl, water, 5% NaHCO3, brine, and dried over anh. MgSO4 and concentrated to give a solid residue. Crystallization from CHCl3 /pentane gave the title compound identical with the most polar isomer obtained in Example 1. One hour after the addition the reaction mixture was brought to room temperature and three hours later, the reaction mixture was washed with 20 ml each of 5% HCl, water, 5% NaHCO3, brine dried over anh. MgSO4 concentrated to give a solid residue Crystallization from CHCl3 /pentane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of N-benzyloxycarbonyl-L-phenylalanine, 0.84 gm, at -20° C. in 50 ml of dry CHCl3, was added N-methyl piperidine, 0.34 ml, with stirring under argon. After 5 minutes, isobutyl chloroformate, 0.36 ml, was added dropwise and after 20 minutes, 5-aminomethyl-3-bromo-4,5-dihydroisoxazole, [optically active [α]D23 =+208.6(CH2Cl2)] 0.5 gm, was added dropwise in 10 ml of dry CHCl3. One hour after the addition, the reaction mixture was brought to room temperature and three hours later, the reaction mixture was washed with 20 ml each of 5% HCl, water, 5% NaHCO3, brine, and dried over anh. MgSO4 and concentrated to give a solid residue. Crystallization from CHCl3 /pentane gave the title compound identical with the most polar isomer obtained in Example 1. One hour after the addition the reaction mixture was brought to room temperature and three hours later, the reaction mixture was washed with 20 ml each of 5% HCl, water, 5% NaHCO3, brine dried over anh. MgSO4 concentrated to give a solid residue Crystallization from CHCl3 /pentane