反応 #214350

反応方程式

isopropenylacetate

benzene

9β,11β-epoxy-21-acetoxy-17-hydroxy-pregna-1,4-diene-3,20-dione

→

3,21-diacetoxy-17-hydroxy-9β,11β-epoxy-pregna-1,3,5-triene-20-one

反応条件

後処理

1. 1
   温度The mixture was heated
2. 2
   温度under reflux for 5 hours
3. 3
   温度cooled
4. 4
   ろ過filtered an the filtrate
5. 5
   その他was evaporated to dryness
6. 6
   その他The residue which crystallized from methanol (0,5% pyridine)
7. 7
   その他gave

実験手順

10 g of sulfonic acid resin (Amberlite I R120, marketed by Rohm and Haas Co.) was dehydrated by azeotropic destillation with benzene. The dry resin was suspended in 50 ml isopropenylacetate and 10 g 9β,11β-epoxy-21-acetoxy-17-hydroxy-pregna-1,4-diene-3,20-dione were added. The mixture was heated under reflux for 5 hours, cooled and filtered an the filtrate was evaporated to dryness. The residue which crystallized from methanol (0,5% pyridine) gave in high yield (9,5 grams) 3,21-diacetoxy-17-hydroxy-9β,11β-epoxy-pregna-1,3,5-triene-20-one. Melting point: 194° C., λmax 310 nm (ε5500)⟦alpha⟧sub.D in chloroform -199° C. (c=1% chloroform), νmax (cm-1) (K Br) 3450; 1765; 1740; 1725; 1655; 1625; 1590.

出典