[OH:1][C@H:2]1[CH2:6][CH2:5][NH:4][CH2:3]1.C1(C)C=CC=CC=1.C(N(CC)CC)C.[CH2:21]([O:28][C:29](Cl)=[O:30])[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1>ClCCl>[OH:1][C@H:2]1[CH2:6][CH2:5][N:4]([C:29]([O:28][CH2:21][C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)=[O:30])[CH2:3]1A 0.5 g portion of (S)-3-hydroxypyrrolidine, as described in Example 42, was reconcentrated twice from toluene, dissolved in 80 ml of dichloromethane and cooled to 0° C. A 3.8 ml portion of triethylamine and 2.8 ml of benzylchloroformate were added with stirring. The reaction was stirred overnight, diluted with 300 ml of dichloromethane and extracted with 80 ml of 5% hydrochloric acid and 5% sodium bicarbonate solution. The aqueous phases were combined, saturated with sodium chloride and extracted with 3×150 ml of ethyl acetate. The organic phases were combined, dried, filtered and concentrated in vacuo. The residue was purified by chromatography (alumina) giving 940 g of (S)-3-hydroxy-1-pyrrolidinecarboxylic acid, phenylmethyl ester as a yellow oil [α]D26 =+21° (c, 1.054 methanol).
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