“…The combined organic phases were dried (Na 2 SO 4 ), filtered, and then concentrated under reduced pressure. The resulting yellow oil was subjected to flash chromatography (1:10 v/v ammonia-saturated methanol/chloroform) to afford, after concentration of the appropriate fractions ( R f = 0.4), compound 1 (R,R = CH 2 ) (57 mg, 78%) as a clear, colorless oil. 1 H NMR (400 MHz, CDCl 3 ) δ 6.65 (s, 1H), 6.41 (s, 1H), 5.83 (s, 2H), 4.34 (d, J = 16.6 Hz, 1H), 3.73 (d, J = 16.6 Hz, 1H), 3.36 (m, 1H), 2.86–2.75 (complex m, 2H), 2.29 (m, 1H), 2.19 (m, 1H), 1.80–1.72 (complex m, 4H), 1.57 (m, 1H), 1.47 (m, 1H), 1.27–1.13 (complex m, 2H); 13 C NMR (100 MHz, CDCl 3 ) δ 146.2, 145.5, 141.6, 125.1, 106.1, 103.1, 100.6, 67.3, 61.6, 51.7, 42.7, 37.4, 28.7, 27.1, 24.1, 21.5; IR (KBr): ν max 2931, 2855, 1503, 1481, 1310, 1232, 1094, 1039 cm –1 ; MS (EI, 70 eV): m / z 257 (M +· , 100%); HRMS M +· Calcd for C 16 H 19 NO 2 : 257.1416, Found: 257.1417; [α] D 20 = −11.6 ( c = 1, CHCl 3 ).…”