Reacción #87466

Ecuación de reacción

Triethylamine

oxalyl dichloride

dimethyl sulfoxide

(3R,4S,5S)-3,4,5-tris-benzyloxy-6,6-bis-(4-methoxy-benzyloxymethyl)-tetrahydro-pyran-2-ol

→

(3R,4S,5S)-3,4,5-tris-benzyloxy-6,6-bis-(4-methoxy-benzyloxymethyl)-tetrahydro-pyran-2-one

Rendimiento 72.0%

Disolventes

dichloromethane

dichloromethane

dichloromethane

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGthe resulting mixture was stirred for 30 minutes
2. 2
   Otroto rise to −60° C
3. 3
   OtroThe reaction was quenched by addition of saturated aqueous ammonium chloride solution
4. 4
   Secadothe organic phase was dried over magnesium sulfate
5. 5
   Filtraciónfiltered
6. 6
   Concentraciónconcentrated under reduced pressure
7. 7
   OtroThe crude material was purified by flash chromatography over silica gel eluting with a gradient of 0 to 60% ethyl acetate in heptane
8. 8
   Otroto produce the product (I-1e) (4 g, 72% yield)

Procedimiento

To a solution of oxalyl dichloride (1.9 mL, 23 mmol) in dichloromethane (65 mL) at −78° C. was added a solution of dimethyl sulfoxide (3.3 mL, 47 mmol) in dichloromethane (5 mL) and the resulting solution was stirred at this temperature for 30 minutes. A solution of starting material ((3R,4S,5S)-3,4,5-tris-benzyloxy-6,6-bis-(4-methoxy-benzyloxymethyl)-tetrahydro-pyran-2-ol, (I-1d, 5.6 g, 7.7 mmol) in dichloromethane (15.0 mL) was then added dropwise and the resulting mixture was stirred for 30 minutes allowing the temperature to rise to −60° C. Triethylamine (9.7 mL, 69.5 mmol) was added dropwise and the mixture allowed to warm up to 0° C. over 1 hour. The reaction was quenched by addition of saturated aqueous ammonium chloride solution and the organic phase was dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude material was purified by flash chromatography over silica gel eluting with a gradient of 0 to 60% ethyl acetate in heptane to produce the product (I-1e) (4 g, 72% yield).

Fuente