Neopentyl glycol → 20-(5,5-Dimethyl-1,3-dioxan-2-yl)-7alpha-hydroxypregna-1,4-dien-3one

HRID 1196311Notes

Reaction equation

HRID 1196311 reaction equation
[OH:1][C@@H:2]1[CH2:22][C:21]2[C@:16]([CH3:24])([CH:17]=[CH:18][C:19](=[O:23])[CH:20]=2)[C@@H:15]2[C@@H:3]1[C@H:4]1[C@:12]([CH3:25])([CH2:13][CH2:14]2)[C@@H:7]([CH:8]([CH:10]=[O:11])[CH3:9])[CH2:6][CH2:5]1.[CH3:26][C:27]([CH3:32])([CH2:30]O)[CH2:28][OH:29].C(OCC)(=O)C.CCCCCC>C(Cl)Cl.C1(C)C=CC(S(O)(=O)=O)=CC=1>[CH3:26][C:27]1([CH3:32])[CH2:28][O:29][CH:10]([CH:8]([C@@H:7]2[C@:12]3([CH3:25])[C@H:4]([C@H:3]4[C@H:15]([CH2:14][CH2:13]3)[C@:16]3([CH3:24])[C:21](=[CH:20][C:19](=[O:23])[CH:18]=[CH:17]3)[CH2:22][C@H:2]4[OH:1])[CH2:5][CH2:6]2)[CH3:9])[O:11][CH2:30]1

Participants

6

Reactant 3

HCID 31344Neopentyl glycolHCID 21226206Ethyl acetate hexaneHCID 228438847-Hydroxy-pregna-1,4-dien-3-one-20-carbaldehyde

Product 1

HCID 2284393020-(5,5-Dimethyl-1,3-dioxan-2-yl)-7alpha-hydroxypregna-1,4-dien-3oneYield 50.2%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 6344DichloromethaneSolvent

Procedure

In 200 ml of methylene chloride were dissolved 5.00 g (14.6 mmoles) of 7α-hydroxypregna-1,4-dien-3-one-20-carbaldehyde and 4.56 g (43.8 mmoles) of 2,2-dimethyl-1,3-propanediol, followed by addition of 100 mg of p-toluenesulfonic acid and 20 g of molecular sieve 4A 1/16. The mixture was stirred gently at room temperature for 12 hours. From the reaction mixture thus obtained, the molecular sieve was filtered off and the solvent in the filtrate was distilled off under reduced pressure. Finally the residue was purified by silica gel chromatography (eluent: ethyl acetate-hexane =1:10, v/v) to give 3.14 g of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-7α-hydroxypregna-1,4-dien-3-one (yield: 50%).

Workup

  1. customFrom the reaction mixture thus obtained
  2. filtrationthe molecular sieve was filtered off
  3. distillationthe solvent in the filtrate was distilled off under reduced pressure
  4. customFinally the residue was purified by silica gel chromatography (eluent

Sources & evidence

ORD record
ord-84a242ae33954b16bdd9a293849edb7a
Source dataset
uspto-grants-1992_05
Patent number
US05112998

Reaction notes

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