Reaktion #40594

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

methanesulfonyl chloride

NEt3

→

white solid

Ausbeute 32.0%

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

Ausbeute 32.0%

Lösungsmittel

CH2Cl2

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenthe mixture was washed with saturated NaHCO3 (20 mL) and saturated NaCl (2×15 mL)
2. 2
   Trocknendried (Na2SO4)
3. 3
   SonstigeThe solvent was removed under reduced pressure
4. 4
   SonstigeThe resulting crude solid was purified by column chromatography (eluent: ethyl acetate/n-hexanes)

Vorschrift

A solution of 8a (0.05 g, 0.13 mmol), methanesulfonyl chloride (1 mL) and NEt3 (2 mL) in CH2Cl2 (30 mL) was stirred at room temperature overnight and then the mixture was washed with saturated NaHCO3 (20 mL) and saturated NaCl (2×15 mL) and dried (Na2SO4). The solvent was removed under reduced pressure. The resulting crude solid was purified by column chromatography (eluent: ethyl acetate/n-hexanes) to afford 0.02 g (32%) of a white solid, mp 147-150° C.; 1H NMR (CDCl3): δ 1.14 (3H, s, H-19); 1.47 (3H, s, H-20); 1.50-1.70 (3H, m, H-7α,β and H-11β); 1.81 (1H, m, H-6α); 2.11 (1H, dd, J=2.9, 11.3 Hz, H-8); 2.16 (1H, s, H-10); 2.19 (1H, m, H-6β); 2.42 (1H, dd, J=13.2, 13.2 Hz, H-3α); 2.50 (1H, m, H-3β); 2.52 (1H, dd, J=4.8, 13.2 Hz, H-11α); 2.75 (1H, dd, J=3.6, 13.2 Hz, H-4); 3.25 (3H, s, CH3SO2); 3.74 (3H, s, CO2CH3); 5.07 (1H, dd, J=8.0, 12.2 Hz, H-2); 5.55 (1H, dd, J=5.1, 11.7 Hz, H-12); 6.41 (1H, dd, J=0.9, 1.8 Hz, H-14); 7.42 (1H, dd, J=1.8, 1.8 Hz, H-15); 7.45 (1H, br d).

Quelle