反应 #87486

反应方程式

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

收率 72.0%

溶剂

dichloromethane

dichloromethane

dichloromethane

反应条件

后处理

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

实验过程

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).

来源