反应详情

5,6α-epoxicholest-7-en-3β-ol (8.9 g, 22.1 mmol, 1 eq) and putrescine (3.9 g, 44.1 mmol, 2 eq) were charged in a round-bottomed flask equipped with a magnetic stirrer bar. 1-Butanol (70 ml, 5 vol) was added and the mixture heated to reflux for 40 h. The reaction mixture was cooled at r.t., diluted with methyl-tertbutyl-ether (5 vol) and washed with water (5 vol) and with brine (5 vol). The organic layer was passed through a silica pad (40 g) eluted with methyl-tertbutyl-ether (3 vol) then 10% Methanol/ethyl acetate (60 vol). Fractions of interest were pooled and the solvent was removed under reduced pressure to give 5α-Hydroxy-6β-(4-aminobutylamino)-cholest-7-en-3β-ol as a white solid (6.9 g, 64%). In same conditions, use of ethanol as solvent (40 vol) and Ca(OTf)2 as catalyst gave a 23% yield.

1. customequipped with a magnetic stirrer bar
2. temperaturethe mixture heated
3. temperatureto reflux for 40 h
4. washwashed with water (5 vol) and with brine (5 vol)
5. washeluted with methyl-tertbutyl-ether (3 vol)
6. customthe solvent was removed under reduced pressure