반응 #214350

반응 방정식

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

반응 조건

후처리

1. 1
   온도The mixture was heated
2. 2
   온도under reflux for 5 hours
3. 3
   온도cooled
4. 4
   여과filtered an the filtrate
5. 5
   기타was evaporated to dryness
6. 6
   기타The residue which crystallized from methanol (0,5% pyridine)
7. 7
   기타gave

실험 절차

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.

출처