反应详情

Add palladium (II) acetate (2.31 g; 0.298 mmol) to a stirred solution of (3S)-3-(1-hydroxy-but-3-enyl)-pyrrolidine-1-carboxylic acid tert-butyl ester (S-mix) (14.4 g, 59.7 mmol) in dichloromethane (43.2 mL). Add slowly a freshly prepared solution of diazomethane (100 mL, about 50 mmol in diethyl ether) under nitrogen at −30 to −40° C. (Caution: vigorous N2 gas evolution). Evaporate the solvent and dissolve the crude in dichloromethane (43.2 mL). Add palladium (II) acetate (2.31 g, 0.298 mmol) followed by a freshly prepared solution of diazomethane (100 mL, about 50 mmol in diethyl ether) to the mixture kept under nitrogen at −30 to −40° C. (Caution: vigorous N2 gas evolution). Evaporate the solvent and dissolve the crude in dichloromethane (43.2 mL). Add palladium (II) acetate (2.31 g, 0.298 mmol) followed by a freshly prepared solution of diazomethane (50 mL, about 25 mmol in diethyl ether) to the mixture kept under nitrogen at −30 to −40° C. (Caution: vigorous N2 gas evolution). Evaporate the solvent, add hexanes (140 mL) to the crude residue and stir the suspension over night at room temperature. Filter the suspension over a pad of celite® and concentrate to obtain a quantitative yield (3S)-3-(2-cyclopropyl-1-hydroxyethyl)pyrrolidine-1-carboxylic acid tert butyl ester (S-mix). MS (m/z)=200.1 [M−55].

1. customEvaporate the solvent
2. dissolutiondissolve the crude in dichloromethane (43.2 mL)
3. customkept under nitrogen at −30 to −40° C.
4. customEvaporate the solvent
5. dissolutiondissolve the crude in dichloromethane (43.2 mL)
6. customkept under nitrogen at −30 to −40° C.
7. customEvaporate the solvent
8. additionadd hexanes (140 mL) to the crude residue
9. filtrationFilter the suspension over a pad of celite®
10. concentrationconcentrate