Study On The Selective Dehydrogenation Of △～4-en-3-one Steroids To △～(4,6)-diene-3-one Steroids

Chloranil and 2,3-dichloro-5,6-dicyanobenzoquinone are commonly usedoxidates in the dehydrogenation reaction of steroids, especially for △4-en-3-one-steroids. In the study, these two oxidants are used to dehydrogenate twosubstrates 19-hydroxy-androst-4-en-3,17-dione and estra-4,6-en-3,17-dione toaccompolish 6,7-dehydrogenation. The reaction of chloranil is our emphasis to studyon this paper for the DDQ reactions has come to maturity. Molar ratio, concentration,temperature, solvent, catalyst and some more important factors are studied for thechloranil reaction to get an optimum reaction condition. The comparation betweenchloranil and DDQ on the dehydrogenation reaction of two substrates was achieved,and some side reactions is discussed too.On the dehydrogenation of 19-hydroxy-4-en-androst-3,17-dione, chloranil asoxidant, anhydrous alcohol as solvent, 2% of p-toluenesulfonic acid as catalyst, 50℃,molar ratio of chloranil and substrate―1.2:1, concentration of substrate―0.025g/mL,19-hydroxy-4,6-dien-androst-3,17-dione was obtained with the yield of 60.5%.DDQ as oxidant, benze as solvent, anhydrouse HCl as catalyst, 80℃, molar ratioof DDQ and substrate ― 1:1, concentration of substrate ― 0.017g/mL,19-hydroxy-4,6-dien-androst-3,17-dione was obtained with the yield of 50.0%.On the dehydrogenation of estra-4-ene-3,17-dione, chloranil as oxidant,anhydrous alcohol as solvent, 5% of L-ascorbic acid as catalyst, 50℃, molar ratio ofchloranil and substrate ― 1.2:1, concentration of substrate ― 0.025g/mL,estra-4,6-dien-3,17-dione was obtained through alumina column with the yield of27.6%.DDQ as oxidant, benze as solvent, anhydrouse HCl as catalyst, 80℃, molar ratioof DDQ and substrate ― 1:1, concentration of substrate ― 0.017g/mL,estra-4,6-dien-3,17-dione was obtained with the yield of 35.6%.