Benzophenoneimine (55.3 ul), 2,2-bis(diphenylphosphino)-1,1-binaphthyl (29.3 mg), sodium tert-butoxide (22.6 mg) and Pd2DBA3 (15.3 mg) were added to a toluene (0.5 ml) solution of the compound 319-1 (30 mg). The reaction solution was heated to 100° C. and stirred for 3 hours. Diethyl ether was added to the reaction solution, and the obtained mixture was filtered with Celite. The filtrate was concentrated under reduced pressure. 2 M hydrochloric acid (78.5 ul) was added to a THF (1 ml) solution of the residue, and the obtained mixture was stirred at room temperature for 12 hours. A saturated sodium bicarbonate aqueous solution was added to the reaction solution, and the mixture was extracted with dichloromethane. The organic layer was dried over anhydrous magnesium sulfate and then filtered. The filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (n-heptane:ethyl acetate=9:1 to ethyl acetate), so as to obtain the title compound (17 mg).
