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

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Reaction Steps

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 solution; recrystallize 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).

Provenance & Evidence