Reaction Steps
Compound 15 (484 mg; 0.65 mmol), octanethiol (110 mg; 0.75 mmol; 130 μl), methyltrioctylammonium chloride (ca 10 mg) and cesium carbonate (245 mg; 0.75 mmol) were dissolved in benzene (1 ml) and water (1 ml). The reaction mixture was treated as for compound 21. Chromatography gave the title compound (23) (250 mg) and starting compound 15 (160 mg). Yield (based on consumed 15): 71%; [α]D21 +65.3° (c 1.4; CHCl3); 1H-NMR (CDCl3, TMS) δ 5.57 (dd, 1H, J4',5' =1 Hz, H4'), 5.39 (dd, 1H, J2', 3'=11 Hz, J3',4' =3.5 Hz, H3'), 5.20 (dd, H1, J1', 2' =3.5 Hz, H2'), 5.19 (dd, 1H, J2,3 =11 Hz, J1,2 =7.5 Hz, H2), 5.01 (d, 1H, J1',2' =3.5 Hz, H1'), 4.81 (dd, 1H, J3,4 =3 Hz, H3), 4.51 (d, 1H, J1,2 =7.5 Hz, H1), 2.73, 2.53 (t, 2H each, J=7 Hz, CH2 --S), 2.13, 2.11, 2.08, 2.08, 2.07, 2.04, 1.99 (s, 3H each, CH3 --CO) ppm. 13C-NMR (CDCl3, TMS) 170.7, 170.6, 170.5, 170.4, 170.1, 169.8, 169.1 (CO), 101.2 (Cl), 99.4 (Cl'), 77.1, 72.7, 71.9, 68.6, 68.6, 67.8, 67.4, 67.1 (C2-C5, C2'-C5'), 69.6 (O--CH2 --CH2 --S), 62.0, 60.5 (C6, C6'), 32.6, 31.8, 31.3, 29.8, 29.2, 28.8, 22.7 (aglycon-CH2), 21.0, 20.8, 20.7 (CH3 --CO), 14.1 (CH3 --CH2) ppm.
