Pyridine → Estra-1,3,5(10),7,16-pentaen-3-yl acetate

HRID 2270526Notes

Reaction equation

HRID 2270526 reaction equation
C=[CH:2][C@@H:3]([CH3:24])[C@@H:4]1[C@:21]2(C)[C@H:7]([C@H:8]3[C@H:18]([CH2:19][CH2:20]2)[C@:16]2(C)[C:11](=CC(=O)[CH2:14][CH2:15]2)[CH2:10][CH2:9]3)[CH2:6][CH2:5]1.N1C=CC=CC=1.[C:31]([O:34]C(=O)C)(=[O:33])[CH3:32]>C(OCC)(=O)C>[C:31]([O:34][C:19]1[CH:20]=[CH:21][C:7]2[C@@H:6]3[C:11]([C@H:16]4[C@@:3]([CH2:4][CH2:5]3)([CH3:24])[CH:2]=[CH:14][CH2:15]4)=[CH:10][CH2:9][C:8]=2[CH:18]=1)(=[O:33])[CH3:32]

Participants

5

Reactant 3

HCID 1049PyridineHCID 7918Acetic AnhydrideHCID 1542966021-methylene-20(R)-methylpregn-4-en-3-one

Product 1

HCID 68410585Estra-1,3,5(10),7,16-pentaen-3-yl acetateYield 35.1%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

A solution of estra- 1,3,5(10),7,16-pentaen-3-ol (5, 192.1 mg, 0.7612 mmol) in anh. pyridine (2.6 ml, 32 mmol) and acetic anhydride (0.36 ml, 3.8 mmol) was stirred 6 h, after which 30 ml of ethyl acetate were added. The mixture was washed with three 10 ml portions of 1 N hydrochloric acid+10 ml of saturated sodium bicarbonate+10 ml of brine, dried over magnesium sulfate, and filtered through diatomaceous earth. See Example 15. The residue was washed with 10 ml of ethyl acetate and the combined filtrates were concentrated under reduced pressure. Preparative TLC (5% ethyl acetate/hexanes on silica gel GF, 1000μ thickness) and recrystallization from aqueous ethanol gave fine white needles (78.6 mg, 0.267 mmol, 35%), m.p. 77-80° C. TLC (4% ethyl acetate/hexanes on silica gel) showed 2 spots at Rf 0.21 and 0.24.

Workup

  1. washThe mixture was washed with three 10 ml portions of 1 N hydrochloric acid+10 ml of saturated sodium bicarbonate+10 ml of brine
  2. dry with materialdried over magnesium sulfate
  3. filtrationfiltered through diatomaceous earth
  4. washThe residue was washed with 10 ml of ethyl acetate
  5. concentrationthe combined filtrates were concentrated under reduced pressure
  6. customPreparative TLC (5% ethyl acetate/hexanes on silica gel GF, 1000μ thickness) and recrystallization from aqueous ethanol

Sources & evidence

ORD record
ord-bd53b66ccbc64f988f2ca444881f492e
Source dataset
uspto-grants-2001_12
Patent number
US06331534B1

Reaction notes

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