反应 #554632

反应方程式

CH3COONa

1

tigogenin

CH3COCH3

CH3COOH

→

2

收率 69.5%

3β-Acetoxy-5α-pregn-16-en-20-one

收率 69.5%

溶剂

isopropanol

water

(CH3CO)2O

water

(CH3CO)2O

反应条件

后处理

1. 1
   workup.WAITboiled an additional 2 h
2. 2
   温度cooled to 40° C.
3. 3
   workup.STIRRINGstirred 20 min
4. 4
   温度cooled to room temperature
5. 5
   workup.STIRRINGstirred an additional hour
6. 6
   温度gradually heated
7. 7
   workup.DISTILLATIONto distill off acetone
8. 8
   其他a temperature of 115-117° C.
9. 9
   workup.WAITboiled for 1.5 h
10. 10
    温度cooled to room temperature
11. 11
    workup.ADDITIONtreated with water (425 mL)
12. 12
    过滤The resulting precipitate was filtered off
13. 13
    洗涤washed with water
14. 14
    其他recrystallized from methanol:acetone (3:1)

实验过程

A mixture of 1 (50 g, 120.0 mmol), (CH3CO)2O (150 mL), and C5H5N (10 mL) was boiled for 1 h, cooled to 100° C., stirred, treated with TiCl4 (2.5 g, 13.16 mmol) in (CH3CO)2O (2.5 mL), boiled an additional 2 h, cooled to 40° C., treated gradually with CH3COONa (10 g) dissolved in water (25 mL), stirred 20 min, cooled to room temperature, poured into CH3COCH3 (220 mL) and CH3COOH (220 mL), oxidized by addition of CrO3 (15 g) in water (7.5 mL) at 15-18° C., stirred an additional hour, treated with isopropanol (7.5 mL), gradually heated to distill off acetone and reach a temperature of 115-117° C., boiled for 1.5 h, cooled to room temperature, and treated with water (425 mL). The resulting precipitate was filtered off, washed with water, and recrystallized from methanol:acetone (3:1) to afford 2 (29 g, 69.5%), mp 158-162° C., lit. mp 158-162° C. [2].

来源