Methyl vinyl ketone → 2-butyl-6-methoxy-2-(3-oxobutyl)-3,4-dihydro-1(2H)-naphthalenone

Beteiligte Stoffe

Reaktionsschritte

A solution of 2-butyl-6-methoxy-3,4-dihydro-1(2H)-naphthalenone (230 mg, 1 mmol) in anhydrous tetrahydrofuran (THF, 0.5 mL) was placed under a N2 atmosphere and treated with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, 0.037 mL, 0.25 mmol) followed by methyl vinyl ketone (MVK, 0.104 mL, 1.25 mmol). The mixture was stirred at room temperature for 19 hours and then heated at 60° C. for 80 minutes. Additional MVK (0.104 mL, 1.25 mmol) was added and the mixture was stirred at 60° C. for 2.5 hours. Additional DBU (0.037 mL, 0.25 mmol) was then added and the mixture was stirred at 60° C. for 70 minutes. After cooling to room temperature, the mixture was concentrated under a stream of N2 and the residue was purified by preparative layer chromatography on three 0.1×20×20 cm silica gel GF plates (Analtech, Newark, Del.), developing with 5% EtOAc in CH2Cl2. The UV visible product band was eluted with EtOAc and the eluant was evaporated under vacuum to provide 2-butyl-6-methoxy-2-(3-oxobutyl)-3,4-dihydro-1(2H)-naphthalenone as an oil.

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