Reaction #40603

Reaction equation

39

(2S,4aR,6aR,7R,9S,10aS,10bR)-9-(Amino)-2-(3-furanyl)-dodecahydro-6a,10b-dimethyl-4,10-dioxo-2H-naphtho[2,1-c]pyran-7-carboxylic acid methyl ester

acetic anhydride

→

40

Yield 58.0%

(2S,4aR,6aR,7R,9S,10aS,10bR)-9-(Acetylamino)-2-(3-furanyl)-dodecahydro-6a,10b-dimethyl-4,10-dioxo-2H-naphtho[2,1-c]pyran-7-carboxylic acid methyl ester

Yield 58.0%

Solvents

CH2Cl2

Conditions

Workup

1. 1
   WashThe mixture was washed with 2N HCl (30 mL), 2N NaOH (30 mL), and H2O (30 mL)
2. 2
   Dryingdried (Na2SO4)
3. 3
   OtherRemoval of the solvent under reduced pressure
4. 4
   Otherafforded a crude solid
5. 5
   OtherThe crude solid was purified by column chromatography (eluent: 4% MeOH/CH2Cl2)

Procedure

A solution of 39 (0.06 g, 0.16 mmol), acetic anhydride (0.4 mL, 4.23 mmol) and a catalytic amount of DMAP in CH2Cl2 (30 mL) was stirred at room temperature for 2 h. The mixture was washed with 2N HCl (30 mL), 2N NaOH (30 mL), and H2O (30 mL) and dried (Na2SO4). Removal of the solvent under reduced pressure afforded a crude solid. The crude solid was purified by column chromatography (eluent: 4% MeOH/CH2Cl2) to afford 0.04 g (58%) of 40 as a white solid, mp 222-224° C. (EtOAc/n-hexanes).

Source