methyl (2R)-pyrrolidine-2-carboxylate

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

Procedure: (2R)-proline methylester (1.20 g, 10.0 mmol) was dissolve in DMF (30 mL), and formalin (37% in water, 1.12 mL, 15.0 mmol) and NaBH (OAc)3 (4.20 g, 20.0 mmol) were added portionwise. After 12 h, the reaction material was concentrated in vacuo, and the residue was diluted with NaHCO3 (30 mL). The organic material was extracted with EtOAc, and the organic extracts were dried over MgSO4 and concentrated in vacuo. The residue was purified by column chomatography (EtOAc/Hex=4/1) to give the title compound (1.33 g, 93.0%). the reaction material was concentrated in vacuo the residue was diluted with NaHCO3 (30 mL) The organic material was extracted with EtOAc the organic extracts were dried over MgSO4 concentrated in vacuo The residue was purified by column chomatography (EtOAc/Hex=4/1)

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

Procedure: N-triphenylmethyl-2-paranitrophenoxycarbonylthioethylamine (675 mg) and D-proline methylester (0.18 g) were subjected to similar reactions to those described in References 2 and 4 to give 2-[(R)-2-methoxycarbonylpyrrolidino]carbonylthioethylamine (crude formate: 336 mg). The product was dissolved in anhydrous methanol (6 ml). To the solution were added triethylamine (1.01 ml) and mitomycin A (338 mg: 0.8 molar equivalent). The solution was then treated in a similar manner to that described in Example 1 to obtain Compound 32 (286 mg) in the form of grayish blue powders with a yield of 43%.