2-Butyl-1,3-cyclopentanedione → 13beta-Butyl-3-methoxygona-1,3,5(10),8,14-pentaen-17-one

HRID 1414965Notes

Reaction equation

HRID 1414965 reaction equation
[CH2:1]([CH:5]1[C:9](=[O:10])[CH2:8][CH2:7][C:6]1=O)[CH2:2][CH2:3][CH3:4].[CH3:12][O:13][C:14]1[CH:15]=[C:16]([CH2:20][CH2:21][CH2:22][C:23](=O)[CH:24]=[CH2:25])[CH:17]=[CH:18][CH:19]=1>[OH-].[K+]>[CH2:1]([C@:5]12[CH2:6][CH2:7][C:8]3[C:17]4[CH:18]=[CH:19][C:14]([O:13][CH3:12])=[CH:15][C:16]=4[CH2:20][CH2:21][C:22]=3[C:23]1=[CH:24][CH2:25][C:9]2=[O:10])[CH2:2][CH2:3][CH3:4]

Participants

4

Reactant 2

HCID 5744932-Butyl-1,3-cyclopentanedioneHCID 107982386-m-Methoxyphenylhex-1-en-3-one

Product 1

HCID 5412707213beta-Butyl-3-methoxygona-1,3,5(10),8,14-pentaen-17-oneYield 32.5%

Reagents, catalysts & solvents 1

HCID 14797Potassium HydroxideSolvent

Procedure

Condense n-butylcyclopentane-1,3-dione (2.8 g) in 0.12% methanolic potassium hydroxide solution (8 cc) with 6-m-methoxyphenylhex-1-en-3-one (5 g) by heating the mixture at 80° for 10 hours. Evaporate the solvent under reduced pressure and heat the residue with toluene-p-sulfonic acid (2 g) in benzene (50 cc) for 45 minutes using a Dean-Stark trap to effect double cyclodehydration. Add ether to the cooled reaction mixture, and evaporate the washed and dried ether solution; recrystallize the residue from ethanol to obtain 13β-butyl-3-methoxygona-1,3,5(10),8,14-pentaen-17-one (1.9 g), m.p. 53°-55°; ultraviolet absorption peak at 312 mμ (ε29,200).

Workup

  1. temperatureby heating the mixture at 80° for 10 hours
  2. customEvaporate the solvent under reduced pressure
  3. temperatureheat the residue with toluene-p-sulfonic acid (2 g) in benzene (50 cc) for 45 minutes
  4. customAdd ether to the cooled reaction mixture
  5. customevaporate the
  6. washwashed
  7. customrecrystallize the residue from ethanol

Sources & evidence

ORD record
ord-22ab936161284859866290ed9c92f6ef
Source dataset
uspto-grants-1977_01
Patent number
US04002746

Reaction notes

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