Reacción #40593

Ecuación de reacción

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

benzoyl chloride

MeOH

→

13

Rendimiento 98.0%

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

Rendimiento 98.0%

Disolventes

CH2Cl2

Condiciones de reacción

Tratamiento posterior

1. 1
   Otrothe solvent was removed under reduced pressure
2. 2
   workup.ADDITIONCH2Cl2 (25 mL) was added to the residue
3. 3
   Lavadothe solution was washed with 10% HCl (3×20 mL) and saturated NaCl (3×20 mL)
4. 4
   Secadodried (Na2SO4)
5. 5
   OtroRemoval of the solvent under reduced pressure

Procedimiento

A solution of 8a (0.05 g, 0.13 mmol), benzoyl chloride (0.09 g, 0.92 mmol) and a catalytic amount of DMAP in CH2Cl2 (20 mL) was stirred at room temperature for 2 h. Absolute MeOH (15 mL) was added and the solvent was removed under reduced pressure. CH2Cl2 (25 mL) was added to the residue and the solution was washed with 10% HCl (3×20 mL) and saturated NaCl (3×20 mL) and dried (Na2SO4). Removal of the solvent under reduced pressure afforded 13 (0.06 g, 98%) as a white solid, mp 165-170° C.; 1H NMR (CDCl3): δ 1.18 (3H, s, H-19); 1.47 (3H, s, H-20); 1.50-1.75 (4H, m, H-6β, H-7α,β and H-11β); 1.84 (1H, ddd, J=3.0, 3.0, 9.9 Hz, H-6α); 2.11 (1H, dd, J=2.4, 10.8 Hz, H-8); 2.26 (1H, s, H-10); 2.47 (2H, m, H-3α,β); 2.55 (1H, dd, J=5.1, 13.5 Hz, H-11α); 2.84 (1H, dd, J=6.9, 9.9 Hz, H-4); 3.75 (3H, s, CO2CH3); 5.40 (1H, dd, J=9.6, 10.5 Hz, H-2); 5.52 (1H, dd, J=2.1, 11.7 Hz, H-12); 6.39 (1H, dd, J=0.9, 1.8 Hz, H-14); 7.40 (1H, dd, J=1.5, 1.8 Hz, H-15); 7.42 (1H, dd, J=0.9, 1.5 Hz, H-16); 7.48 (2H, dt, J=7.2, 7.5 Hz, Ar-meta-H); 7.60 (1H, tt, J=1.2, 7.5 Hz, Ar-para-H); 8.09 (2H, dt, J=1.2, 7.2 Hz, Ar-ortho-H).

Fuente