1-((1S)-1-isocyanatoethyl)naphthalene → (1-Naphthalen-1-yl-ethyl)-carbamic acid-4-benzo [1,3]dioxol-5-yl-2-(4-methoxy-phenyl)-5-oxo-3-(3,4,5-trimethoxy-benzyl)-2,5-dihydro-furan-2-yl ester

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Reaction Steps

To 15 mL dichloromethane was added 3-benzo[1,3]dioxol-5-yl-5-hydroxy-5-(4-methoxyphenyl)-4-(3,4,5-trimethoxy-benzyl)-5H-furan-2-one 1.00 g (1.98 mmol) and stirred to dissolve. To this was added (S)-1-(1-naphthyl)ethyl isocyanate 414 mg (2.1 mmol) and a catalytic amount of 4-dimethylaminopyridine 20 mg (0.164 mmol). The mixture was stirred at room temperature for 24 hours. The solution was washed with 50 mL water and 50 mL brine, and the organic phase was separated and dried over magnesium sulfate, then evaporated to dryness. The crude product was then purified by flash chromatography (150 g silica gel, 10% EtOAc/CH2Cl2). The product was isolated by evaporation of the appropriate fractions to give 840 mg (60%) as a white foam. The product was identified by 1H NMR, MS, [M+H]+ =704 Da. and microanalysis.

Provenance & Evidence