Tributylphosphine → 20-(5,5-Dimethyl-1,3-dioxan-2-yl)-1alpha, 2alpha-epoxypregna-5,7-dien-3beta-yl acetate

HRID 1708753Notes

Reaction equation

HRID 1708753 reaction equation
C(P(CCCC)CCCC)CCC.[C:14]([O:17][C@H:18]1[C@@H:44]2[O:45][C@@H:43]2[C@@:42]2([CH3:46])[C:20](=[CH:21][C@@H:22](OC(OC)=O)[C@@H:23]3[C@@H:41]2[CH2:40][CH2:39][C@@:38]2([CH3:47])[C@H:24]3[CH2:25][CH2:26][C@@H:27]2[CH:28]([CH:30]2[O:35][CH2:34][C:33]([CH3:37])([CH3:36])[CH2:32][O:31]2)[CH3:29])[CH2:19]1)(=[O:16])[CH3:15]>O1CCOCC1>[C:14]([O:17][C@H:18]1[C@@H:44]2[O:45][C@@H:43]2[C@@:42]2([CH3:46])[C:20](=[CH:21][CH:22]=[C:23]3[C@@H:41]2[CH2:40][CH2:39][C@@:38]2([CH3:47])[C@H:24]3[CH2:25][CH2:26][C@@H:27]2[CH:28]([CH:30]2[O:31][CH2:32][C:33]([CH3:37])([CH3:36])[CH2:34][O:35]2)[CH3:29])[CH2:19]1)(=[O:16])[CH3:15]

Participants

4

Reactant 2

HCID 13831TributylphosphineHCID 8674580120-(5,5-Dimethyl-1,3-dioxan-2-yl)-1alpha,2alpha-epoxy-7alpha-methoxycarbonyloxypregn-5-en-3beta-yl acetate

Product 1

HCID 8674580520-(5,5-Dimethyl-1,3-dioxan-2-yl)-1alpha, 2alpha-epoxypregna-5,7-dien-3beta-yl acetateYield 46.3%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent2×

Procedure

A mixture of 10.3 mg (0.00997 mmole) of tris(dibenzylideneacetone)dipalladium(chloroform), 19.9 μl (0.0798 mmole) of tributylphosphine and 5 ml of dry 1,4-dioxane was stirred in an atmosphere of argon gas at room temperature for 10 minutes. To this mixture was added a solution of 43.6 mg (0.0798 mmole) of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxy-7α-methoxycarbonyloxypregn-5-en-3β-yl acetate in 2 ml of dry 1,4-dioxane, and the mixture was refluxed for 8 hours. The reaction mixture was cooled to room temperature and filtered through a glass filter with the aid of Florisil. The filtrate was concentrated under reduced pressure and the concentrate was purified by silica gel chromatography (eluent: ether-hexane=1:10, v/v) to give 17.4 mg of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxypregna-5,7-dien-3β-yl acetate. In addition, 15.3 mg of the starting compound 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxy-7α-methoxycarbonyloxypregn-5-en-3β-yl acetate was recovered. The yield of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxypregna-5,7-dien-3β-yl acetate was 71% based on consumed 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxy-7α-methoxycarbonyloxypregn-5-en-3β-yl acetate.

Workup

  1. temperaturethe mixture was refluxed for 8 hours
  2. temperatureThe reaction mixture was cooled to room temperature
  3. filtrationfiltered through a glass
  4. filtrationfilter with the aid of Florisil
  5. concentrationThe filtrate was concentrated under reduced pressure
  6. customthe concentrate was purified by silica gel chromatography (eluent

Sources & evidence

ORD record
ord-296b43a1a51b4c93879c81aeb366c711
Source dataset
uspto-grants-1994_10
Patent number
US05359055

Reaction notes

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