Sodium Cyanide → Mangostin
Reaction equation
[CH3:1][C:2]([CH3:29])=[CH:3][CH2:4][C:5]1[C:6]([OH:28])=[CH:7][C:8]2[O:27][C:15]3[CH:16]=[C:17]([OH:26])[C:18]([OH:25])=[C:19]([CH2:20][CH:21]=[C:22]([CH3:24])[CH3:23])[C:14]=3[C:12](=[O:13])[C:9]=2[C:10]=1[OH:11].[C-:30]#N.[Na+]>CS(C)=O>[CH3:1][C:2]([CH3:29])=[CH:3][CH2:4][C:5]1[C:10]([OH:11])=[C:9]2[C:12]([C:14]3[C:15]([O:27][C:8]2=[CH:7][C:6]=1[OH:28])=[CH:16][C:17]([OH:26])=[C:18]([O:25][CH3:30])[C:19]=3[CH2:20][CH:21]=[C:22]([CH3:23])[CH3:24])=[O:13]Participants
4
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 195 °C
Procedure
Conversion of 6,7-di-O-methyl-γ-mangostin to γ-mangostin: To a solution of 6,7-di-O-methyl-γ-mangostin (0.5 g) in DMSO (LR, 20 mL) was added sodium cyanide (1.0 g) at RT and the mixture was stirred at 190-200° C. for 6 h. The reaction mixture was cooled to ambient temperature and poured into ice cold water. The mixture was extracted with a mixture of ethyl acetate and THF (1:1, 5×100 mL). The combined organic layer was washed with aqueous potassium permanganate (10%), water, brine and dried over sodium sulfate. The solution was filtered and the solvent evaporated. The residue was chromatographed over silica gel column using chloroform/methanol mixture (95:5) as eluent to give α-mangostin (330 mg, 68%). The α-mangostin was then converted to γ-mangostin using the inventive demethylation procedure as described in example 12.