“…The residue was chromatographed on silica gel and the eluate of benzene-ethyl acetate (4 : 1) was evaporated and the residue was recrystallized from methanol to give 10b (243 mg, 69%) as colorless prisms, mp 121-122°C. 1 (3H, 1H, 1H, 3H, each m, H-5, 6, 7, 1Ј), 3.39, 3.65 (each 2H, each …”