HCID 11076344, compound → HCID 10967937, compound

Participants

Reaction Steps

0.05 M Na2HPO4 aqueous solution (16.6 ml) was added to 0.55 M NaOCl aqueous solution (41.5 ml, 22.8 mmol) at 0° C. To the aqueous solution was slowly added the solution of (2S)-6-nitro-2-methyl-2-dimethoxymethyl-2H-1-benzopyran (1.5 g, 5.7 mmol) and (S,S)-Mn(III) salen, catalyst (155 mg, 0.28 mmol) for an enantioselective epoxidation developed by Jacobsen in dichloromethane (8.5 ml). The solution was stirred at the room temperature for 12 hours. After the reaction was completed, the reaction mixture was filtered to remove the catalyst and the filtrate was extracted with dichloromethane (200 ml). The dichloromethane layer was washed with saturated brine solution, dried over anhydrous magnesium sulfate and concentrated to remove the dichloromethane. The crude product was purified by chromatography (developing solvent—n-hexane:ethyl acetate=4:1) to give (2S,3S,4S)-6-nitro-2-methyl-2-dimethoxymethyl-3,4-epoxy-3,4-dihydro-2H-1-benzopyran, the compound of formula 2 (1.4 g, yield: 88%).

Provenance & Evidence