Ethyl Acetate → Sarsagenin

HRID 1438956Notes

Reaction equation

HRID 1438956 reaction equation
[CH3:1][C@@H:2]1[CH2:73][O:72][C@@:5]2([O:9][C@H:8]3[CH2:10][C@H:11]4[C@@H:16]5[CH2:17][CH2:18][C@@H:19]6[CH2:24][C@@H:23]([O:25][C@@H]7O[C@H](CO[C@@H]8O[C@H](CO)[C@@H](O)[C@H](O)[C@H]8O)[C@@H](O[C@@H]8O[C@@H](C)[C@H](O)[C@@H](O)[C@H]8O)[C@H](O)[C@H]7O[C@@H]7O[C@H](CO)[C@@H](O)[C@H](O)[C@H]7O)[CH2:22][CH2:21][C@:20]6([CH3:69])[C@H:15]5[CH2:14][CH2:13][C@:12]4([CH3:70])[C@H:7]3[C@@H:6]2[CH3:71])[CH2:4][CH2:3]1.C(OCC)(=O)C>C1(C)C=CC=CC=1>[CH3:1][C@@H:2]1[CH2:73][O:72][C@@:5]2([O:9][C@H:8]3[CH2:10][C@H:11]4[C@@H:16]5[CH2:17][CH2:18][C@@H:19]6[CH2:24][C@@H:23]([OH:25])[CH2:22][CH2:21][C@:20]6([CH3:69])[C@H:15]5[CH2:14][CH2:13][C@:12]4([CH3:70])[C@H:7]3[C@@H:6]2[CH3:71])[CH2:4][CH2:3]1

Participants

4

Reactant 2

HCID 8857Ethyl AcetateHCID 19797719057-61-5

Product 1

HCID 92095SarsageninYield 89.5%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

100 Parts of crude sarsasaponin is suspended in 255 parts of ethyl acetate and heated at reflux for 0.5 hour. The mixture is filtered hot and the filter cake washed with 89 parts ethyl acetate and dried. The dried residue is mixed with 1850 parts by volume of a 15% (v/v) solution of concentrated hydrochloric acid in water and heated at 95°-101° C. for 2 hours. The hot reaction mixture is then filtered to give a precipitate which is washed with water and dried to afford crude sarsasapogenin in an 89.5% yield. This crude material is treated with 50 parts alumina and 5 parts carbon in 440 parts toluene. Filtration affords a pale yellow solution, which upon standing, yields a solid. This solid is filtered, and recrystallized from hot n-hexane to give sarsasapogenin melting at about 200°-205° C. This compound exhibits an [α]D25 = -78.8° ±1.5 (c=0.996% in chloroform), an [α]36525 = -230.9° ±1.5 (c=0.996% in chloroform), and is represented by the following structural formula. ##STR1##

Workup

  1. temperatureheated
  2. temperatureat reflux for 0.5 hour
  3. filtrationThe mixture is filtered hot
  4. washthe filter cake washed with 89 parts ethyl acetate
  5. customdried
  6. additionThe dried residue is mixed with 1850 parts by volume of a 15% (v/v) solution of concentrated hydrochloric acid in water
  7. temperatureheated at 95°-101° C. for 2 hours
  8. filtrationThe hot reaction mixture is then filtered
  9. customto give a precipitate which
  10. washis washed with water
  11. customdried
  12. customto afford crude sarsasapogenin in an 89.5% yield
  13. filtrationFiltration
  14. customaffords a pale yellow solution, which
  15. customyields a solid
  16. filtrationThis solid is filtered
  17. customrecrystallized from hot n-hexane

Sources & evidence

ORD record
ord-31b4e26f2ae640469e4b46174bd8e226
Source dataset
uspto-grants-1977_11
Patent number
US04057543

Reaction notes

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