反応 #87486

反応方程式

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

収率 72.0%

溶媒

dichloromethane

dichloromethane

dichloromethane

反応条件

後処理

1. 1
   workup.STIRRINGthe resulting mixture was stirred for 30 minutes
2. 2
   その他to rise to −60° C
3. 3
   その他The reaction was quenched by addition of saturated aqueous ammonium chloride solution
4. 4
   乾燥the organic phase was dried over magnesium sulfate
5. 5
   ろ過filtered
6. 6
   濃縮concentrated under reduced pressure
7. 7
   その他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
   その他to produce the product (I-1e) (4 g, 72% yield)

実験手順

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).

出典