Reacción #92660

Ecuación de reacción

5,6α-epoxicholest-7-en-3β-ol

spermidine

1-Butanol

→

Dendrogenin B

Rendimiento 58.0%

Disolventes

methyl-tertbutyl-ether

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroequipped with a magnetic stirrer bar
2. 2
   Temperaturathe mixture heated
3. 3
   Temperaturato reflux for 40 h
4. 4
   Lavadowashed with water (5 vol) and with brine (5 vol)
5. 5
   Lavadoeluted with methyl-tertbutyl-ether (3 vol)
6. 6
   Otrothe solvent was removed under reduced pressure

Procedimiento

5,6α-epoxicholest-7-en-3β-ol (8.9 g, 22.1 mmol, 1 eq) and spermidine (6.4 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 Dendrogenin B (5α-Hydroxy-6β-[4-(3-aminopropylamino)-butylamino]-cholest-7-en-3β-ol) as a white solid (7.0 g, 58%). In same conditions, use of ethanol as solvent (40 vol) and Ca(OTf)2 as catalyst gave a 14% yield.

Fuente