Reacción #40600

Ecuación de reacción

salvinorin B

(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

triphenylphosphine

bromoform

triphenylphosphine

bromoform

→

36

Rendimiento 59.0%

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

Rendimiento 59.0%

Disolventes

CH2Cl2

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITwas still present after 16 h
2. 2
   workup.STIRRINGthe mixture was stirred for an additional 3 h
3. 3
   OtroThe solvent was removed under reduced pressure
4. 4
   Otroaffording a crude solid
5. 5
   OtroThe oil was purified by column chromatography (eluent: 30% EtOAc/n-hexanes)

Procedimiento

A mixture of salvinorin B (8a) (0.15 g, 0.38 mmol), triphenylphosphine (0.21 g, 0.80 mmol), and bromoform (0.15 g, 0.45 mmol) in CH2Cl2 (30 mL) was stirred at room temperature overnight. TLC indicated that starting material was still present after 16 h, thus additional triphenylphosphine (0.11 g, 0.42 mmol) and bromoform (0.07 g, 0.21 mmol) were added and the mixture was stirred for an additional 3 h. The solvent was removed under reduced pressure affording a crude solid. The oil was purified by column chromatography (eluent: 30% EtOAc/n-hexanes) to afford 0.10 g (59%) of 36 as a white solid, mp 170-173° C. (EtOAc/n-hexanes); 1H NMR (CDCl3): δ 1.15 (3H, s); 1.48 (3H, s); 1.60 (3H, m); 1.81 (1H, dd, J=2.7, 9.9); 1.95 (1H, dd, J=13.2, 26.1); 2.1 (2H, m); 2.27 (1H, s); 2.47 (1H, dd, J=4.8, 13.2); 2.66 (1H, m); 2.80 (1H, dd, J=3.3, 13.2); 3.70 (3H, s); 3.89 (2H, d, J=2.4); 4.45 (1H, m); 5.55 (1H, dd, J=4.8, 11.7); 6.38 (1H, dd, J=0.9, 1.5); 7.4 (2H, m).

Fuente