Dichloromethane → HCID 53701063, compound

Participants

Reaction Steps

Parallel syntheses for the D-isomer (R1 =H, R2 =benzyl) and L-isomer (R1 =benzyl, R2 =H) were performed. The following procedure was used for each. The procedure of Example 2, Section B was followed, using t-butoxycarbonyl-D-phenylalanine for one isomer and t-butoxycarbonyl-L-phenylalanine for the other, and using L-leucyl-L-alanine 4-nitrobenzylamide of the formula ##STR28## instead of (-)N-(L-2-hydroxy-4-methylpentanoyl)-L-alanine 4-nitrobenzyl amide. The reaction was carried out on a 2.0 mmol scale, using methylene chloride (10 mL) instead of dimethylformamide as the solvent. After the extractions, the crude product was purified by silica gel chromatography, eluting with 7:3 methylene chloride:ethyl acetate to afford the products as white solids (D-isomer: 0.83 g, 1.42 mmol, 71% yield; L-isomer: 0.77 g, 1.3 mmol, 62% yield). Verification of the structures was as follows:

Provenance & Evidence