Reaction Steps
A solution of the allyl ether 49 (688 mg, 0.627 mmol) in MeOH (6 mL) and 1,2-dichloroethane (6 mL) (0.05 M) was treated with solid palladium chloride (25 mg). The mixture was stirred at 70° C. (external oil bath) for 2 h. TLC indicated complete conversion. The mixture was evaporated onto silica and purified by column chromatography (silica 2.7×17 cm, gradient elution with hexane-EtOAc 200:20, 200:40, 200:50, 210:70, 200:100) to give the alcohol 50 as a colourless gum (0.539 mg, 81%). 1H NMR (CDCl3, 400 MHz) δ 8.18-8.03 (m, 8H, Ph), 7.85-7.81 (m, 4H, Ph), 7.68-7.25 (m, 23H, Ph), 5.97 (dd or t, 1H, JH3(I)H4(I)=9.8, JH4(I)-H5(I)=9.8, H4I), 5.68 (dd, 1H, J JH1(I)-H2(I)=2.0, JH2(I)-H3(I)=2.9, H2I), 5.60 (dd or t, 1H, J JH3(II)-H4(II)=9.8, J JH4(II)-H5(II)=9.8, H4II), 5.28 (br s, 1H, H1II), 5.15 (d, 1H, J JH1(II)-H2(II)=2.0, H1I), 5.05 (dd, 1H, JH1(II)-H2(II)=2.0, JH2(II)-H3(II)=2.9, H2II), 4.77 (d, 1H, Jgem=11.7, CH2), 4.65-4.56 (m, 4H, CH2, H6Ieq, H3I and H6II), 4.44 (dd, 1H, Jgem=12.7, JH5(I)-H6(I)ax=4.9, H6Iax), 4.34 (m, 1H, H5II), 4.32 (dd, 1H, Jgem=10.7, JH5(II)-H6(II)=2.9, H6II), 4.28 (ddd, 1H, JH5(I)-H6(I)ax=4.9, JH5(I)-H6(I)eq=2.9, H5I), 4.17 (dd, 1H, H3II).
