Reaktion #40597

Reaktionsgleichung

8a

(2S,4aS,6aR,7R,9S,10aS,10bR)-9-(hydroxy)-2-(3-furanyl)dodecahydro-6a,10b-dimethyl-4,10-dioxo-2H-naphtho[2,1-c]pyran-7-carboxylic acid methyl ester

trimethylsilyl chloride

phenylisocyanate

→

22

Ausbeute 14.0%

(2S,4aR,6aR,7R,9S,10aS,10bR)-9-(phenylcarbamoyloxy)-2-(3-furanyl)-dodecahydro-6a,10b-dimethyl-4,10-dioxo-2H-naphtho[2,1-c]pyran-7-carboxylic acid methyl ester

Ausbeute 14.0%

Lösungsmittel

CH2Cl2

Reaktionsbedingungen

Aufarbeitung

1. 1
   WaschenThe reaction mixture was then washed with saturated NaHCO3 (10 mL) and H2O (10 mL)
2. 2
   Trocknendried (Na2SO4)
3. 3
   SonstigeThe solvent was removed under reduced pressure
4. 4
   Sonstigeto give a crude oil
5. 5
   SonstigeThe oil was purified by column chromatography (eluent: ethyl acetate/n-hexanes)

Vorschrift

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).

Quelle