Dicyclohexylcarbodiimide → 2-[1-(trans-2-Pentenoyloxy)-4-methyl-3-pentenyl]-5,8-dihydroxy-1,4-naphthoquinone

Participants

Reaction Steps

288 mg (1 mmole) of shikonin, 226 mg (1.1 mmole) of dicyclohexylcarbodiimide and 30 mg (0.25 mmole) of 4-dimethylaminopyridine were dissolved in 3 ml of dry dichloromethane. To the resulting solution was added 100 mg (1 mmole) of n-pentenoic acid at 0° C. under nitrogen gas, and the mixture was stirred for 30 minutes and then at room temperature for further 3 hours. The resulting product was separated and purified according to the procedures as described in Example 1 to obtain 95 mg (Yield: 23%) of the title compound having the following structure as a red precipitate.

Provenance & Evidence