Chlorotrimethylsilane → (3S,4aR,4bS,6S,8R,8aR,10aR)-3-Furan-3-yl-4a,8a-dimethyl-1,5-dioxo-6-phenylcarbamoyloxy-dodecahydro-2-oxa-phenanthrene-8-carboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

A solution of 8a (0.06 g, 0.14 mmol), trimethylsilyl chloride (0.01 mL, 0.08 mmol) and phenylisocyanate (0.1 mL, 0.92 mmol) in CH2Cl2 was stirred at room temperature for 5 days. The reaction mixture was then washed with saturated NaHCO3 (10 mL) and H2O (10 mL) and dried (Na2SO4). The solvent was removed under reduced pressure to give a crude oil. The oil was purified by column chromatography (eluent: ethyl acetate/n-hexanes) to afford 22 (0.01 g, 14%) as a clear oil: 1H NMR (CDCl3): δ 1.15 (s, 3H); 1.48 (s, 3H); 1.52-1.72 (m, 3H); 1.82 (dd, 1H, 2.7, 10.2 1H); 2.03-2.20 (m, 1H); 2.22 (s, 1H); 2.24-2.48 (m, 2H); 2.54 (dd, Ja=5.1, Jb=13.5, 1H); 2.80 (dd, Ja=3.6, Jb=13.2, 1H); 3.75 (s, 3H); 5.21 (dd, Ja=7.8, Jb=12.3, 1H); 5.54 (dd, J=11.7, 1H); 6.40 (m, 1H), 6.69 (br s, 1H); 6.87 (br s, 1H); 7.12 (m, 2H); 7.28-7.45 (m, 5H).

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