The reaction mixture was quenched with water and extracted with ethyl MK-8776 concentration acetate (3 × 30). The residue obtained after evaporation of the solvent was chromatographed over Dinaciclib datasheet a silicagel column using mixture of ethyl acetate/hexane (30:70) as eluent to produce an oily syrup at an overall yield of 88%. Compound (R,R)-6; Rf = 0.48 (30:70 ethyl acetate/hexane); oily syrup; 1H NMR (400 MHz, CDCl3) δ: 2.08–2.15 (1H, m, H-3), 2.58 (1H, dd, J = 2.6, 7.2 Hz, H-9a), 2.85 (1H, dd, J = 2.6, 7.2 Hz, H-9b), 3.78 (3H, s, Ar–OCH3-5), 3.83 (3H, s, Ar-OCH3-7), 3.99 (2H, d, J = 8.2 Hz, H-2a & 2b), 4.66 (1H, d, J = 2.5 Hz, H-4), 5.99

(1H, d, J = 7.1 Hz, H-8), 6.01 (1H, d, J = 7.1 Hz, H-6), 6.76 (2H, d, J = 8.2 Hz, H-3′,5′), 7.12 (2H, d, J = 8.0 Hz, H-2′,6′); 13C NMR (100 MHz, CDCl3) 31.9 (CH2, C-9), 40.1 (CH, C-3), 55.3 (OCH3, C-7), 55.4 (OCH3, C-5), 59.6 (CH, C-4), 65.2 (CH2, C-2), 91.3 (CH, C-6), 93.0 (CH, C-8), 106.6 (C, C-4a), 115.2 (CH, C-3′,5′), 130.2 (C, C-1′), 131.6 (CH, C-2′,6′), 153.8 (C, C-4′), 155.9 (C, C-5), secondly 159.2 (C, C-8a), 161.1 (C, C-7); mass m/z = 317 (M + 1)+. Compound (R,S)-6; Rf = 0.45 (30:70 ethyl acetate/hexane); oily syrup; 1H NMR (400 MHz, CDCl3) δ: 2.12-2.18 (1H, m, H-3), 2.40 (1H, dd,

J = 2.9, 7.9 Hz, H-9a), 2.55 (1H, dd, J = 2.9, 7.9 Hz, H-9b), 3.76 (3H, s, Ar–OCH3-5), 3.81 (3H, s, Ar–OCH3-7), 3.90 (1H, dd, J = 1.8, 1.8 Hz, H-2a), 4.07 (1H, dd, J = 1.9, 2.0 Hz, H-2b), 4.62 (1H, s, H-4), 6.06 (1H, d, J = 3.9 Hz, H-6), 6.07 (1H, d, J = 3.9 Hz, H-8), 6.74 (2H, d, J = 8.3 Hz, H-3′,5′), 7.04 (2H, d, J = 8.3 Hz, H-2′,6′); 13C NMR (100 MHz, CDCl3) 33.6 (CH2, C-9), 40.5 (CH, C-3), 55.3 (OCH3, C-7), 55.5 (OCH3, C-5), 62.9 (CH, C-4), 64.3 (CH2, C-2), 91.8 (CH, C-6), 93.2 (CH, C-8), 104.9 (C, C-4a), 115.3 (CH, C-3′,5′), 130.2 (C, C-1′), 131.2 (CH, C-2′,6′), 154.2 (C, C-4′), 155.8 (C, C-5), 159.8 (C, C-8a), 161.0 (C, C-7); mass m/z = 317 (M + 1)+. To a mixture of either (R,R)-6 or (R,S)-6 respectively (0.1 g, 1.0 mmol) in acetic acid (4 ml) was added CrO3 (0.16 g, 5.0 mmol).