反応 #359284

反応方程式

triethylamine

2.2-dimethoxypropane

p-toluene sulfonic acid

21

rac-(1S, 2R, 3S, 4R, 5R, 6S)-2,3,4,5-tetrabenzyloxy-1,6-dihydroxy-1-propyl-cyclohexane

→

22

収率 69.3%

rac-(3aR, 4R, 5S, 6S, 7R, 7aS)-4,5,6,7-tetrabenzyloxy-2,2-dimethyl-3a-propyl-hexahydrobenzo-(1,3)-dioxol

収率 69.3%

溶媒

acetone

反応条件

後処理

1. 1
   その他All volatile components were removed under reduced pressure
2. 2
   workup.DISSOLUTIONthe residue was dissolved in t-butylmethyl ether
3. 3
   洗浄washed with 0.5 M phosphate buffer pH=7 and brine
4. 4
   乾燥The organic phase was dried over Na2SO4
5. 5
   ろ過filtered
6. 6
   その他dried under reduced pressure
7. 7
   その他The residue was purified by preparative HPLC (RP18, 94% MeOH, 40 mL/min, tRet=35.10 min)

実験手順

21 (0.22 g, 0.37 mmol) was dissolved in 20 mL dry acetone. 5 mL (40.8 mmol) 2.2-dimethoxypropane and 48 mg (0.25 mmol) p-toluene sulfonic acid were added an the solution was stirred for three days at room temperature. Then the reaction was stopped by adding 150 μL (1.08 mmole) triethylamine. All volatile components were removed under reduced pressure and the residue was dissolved in t-butylmethyl ether and washed with 0.5 M phosphate buffer pH=7 and brine. The organic phase was dried over Na2SO4, filtered and dried under reduced pressure. The residue was purified by preparative HPLC (RP18, 94% MeOH, 40 mL/min, tRet=35.10 min) to give 22 (160 mg, 0.25 mmol, 69.3% yield) as a slightly yellow oil.

出典