合成路线:The dehydrogenation of 16alpha-methyl-11beta,17alpha,21-trihydroxypregna-1,4-diene-3,20-dione-21-acetate (I) with dichlorodicyanobenzoquinone (II) in dioxane HCl gives 16alpha-methyl-11beta,17alpha,21-trihydroxypregna-1,4,6-triene-3,20-dione-21-acetate (III),which is hydrolyzed with aqueous NaHCO3 to the corresponding free triol (IV).The reaction of (IV) with triethyl orthopropionate (A) by means of p-toluenesulfonic acid in DMSO yields 16alpha-methyl-11beta,17alpha,21-trihydroxypregna-1,4,6-triene-3,20-dione-17,21-ethylorthopropionate (V),which is hydrolyzed partially with acetic acid to 16alpha-methyl-11beta,17alpha,21-trihydroxypregna-1,4,6-triene-3,20-dione-17-propionate (VI).The acylation of (VI) with propionic anhydride affords 16alpha-methyl-11beta,17alpha,21-trihydroxypregna-1,4,6-triene-3,20-dione-17,21-dipropionate (VII),which is finally treated with dry HCl in dioxane.
合成路线:The dehydrogenation of 16alpha-methyl-17alpha,21-dihydroxypregna-1,4-diene-3,11,20-trione-21-acetate (VIII) with (II) in dioxane-HCl gives 16alpha-methyl-17alpha,21-dihydroxypregna-1,4,6-triene-3,11,20-trione-21-acetate (IX),which is hydrolyzed with aqueous NaHCO3 to the corresponding free diol (X).The reaction of (X) with triethyl orthopropionate (A) as before yields 16alpha-methyl-17alpha,21-dihydroxypregna-1,4,6-triene-3,11,20-trione-17,21-ethylorthopropionate (XI),which is hydrolyzed partially with acetic acid to 16alpha-methyl-17alpha,21-dihydroxypregna-1,4,6-triene-3,11,20-trione-17-propionate (XII).The acylation of (XII) with propionic anhydride yields the corresponding dipropionate (XIII),which is treated with dry HCl in dioxane to afford 16alpha-methyl-17alpha,21-dihydroxy-7alpha-chloropregna-1,4-diene-3,11,20-trione 17,21-dipropionate (XIV).Finally,this compound is reduced with NaSH4 in methanol - THF.
参考文献标题:Process for the preparation of 7{60 -halogeno-3-oxo-4-dehydro steroids and novel 7{60 -halogeno derivatives produced thereby
文献作者:Green,M.J.; et al.(Schering Corp.)
参考来源:CA 1099254; US 4076708
合成路线:The dehydrogenation of 16alpha-methyl-11beta,17alpha,21-trihydroxypregna-1,4-diene-3,20-dione-21-acetate (I) with dichlorodicyanobenzoquinone (II) in dioxane HCl gives 16alpha-methyl-11beta,17alpha,21-trihydroxypregna-1,4,6-triene-3,20-dione-21-acetate (III),which is hydrolyzed with aqueous NaHCO3 to the corresponding free triol (IV).The reaction of (IV) with triethyl orthopropionate (A) by means of p-toluenesulfonic acid in DMSO yields 16alpha-methyl-11beta,17alpha,21-trihydroxypregna-1,4,6-triene-3,20-dione-17,21-ethylorthopropionate (V),which is hydrolyzed partially with acetic acid to 16alpha-methyl-11beta,17alpha,21-trihydroxypregna-1,4,6-triene-3,20-dione-17-propionate (VI).The acylation of (VI) with propionic anhydride affords 16alpha-methyl-11beta,17alpha,21-trihydroxypregna-1,4,6-triene-3,20-dione-17,21-dipropionate (VII),which is finally treated with dry HCl in dioxane.
合成路线:The dehydrogenation of 16alpha-methyl-17alpha,21-dihydroxypregna-1,4-diene-3,11,20-trione-21-acetate (VIII) with (II) in dioxane-HCl gives 16alpha-methyl-17alpha,21-dihydroxypregna-1,4,6-triene-3,11,20-trione-21-acetate (IX),which is hydrolyzed with aqueous NaHCO3 to the corresponding free diol (X).The reaction of (X) with triethyl orthopropionate (A) as before yields 16alpha-methyl-17alpha,21-dihydroxypregna-1,4,6-triene-3,11,20-trione-17,21-ethylorthopropionate (XI),which is hydrolyzed partially with acetic acid to 16alpha-methyl-17alpha,21-dihydroxypregna-1,4,6-triene-3,11,20-trione-17-propionate (XII).The acylation of (XII) with propionic anhydride yields the corresponding dipropionate (XIII),which is treated with dry HCl in dioxane to afford 16alpha-methyl-17alpha,21-dihydroxy-7alpha-chloropregna-1,4-diene-3,11,20-trione 17,21-dipropionate (XIV).Finally,this compound is reduced with NaSH4 in methanol - THF.
合成路线:In a different method,the primary amine (XVIII) was prepared by reduction of nitrile (XI) with either borane-dimethyl sulfide complex or with LiAlH4.Condensation of amine (XVIII) with acetophenone (I) generated imine (XIX).The asymmetric reduction of (XIX) to furnish the title (R)-amine was accomplished by using LiAlH4 in the presence of several chiral auxiliaries,such as 1,1?binaphthol,(-)-N-methylephedrine,or (-)-N-methylpseudoephedrine,with different degrees of enantioselectivity.Alternatively,imine (XIX) was reduced utilizing a titanium-catalyzed asymmetric hydrosilylation method.
参考文献标题:Chiral reductions of imines leading to the syntheses of optically active amines
文献作者:Van Wagenen,B.C.; Barmore,R.M.(NPS Pharmaceuticals,Inc.)
参考来源:WO 9711934
产品链接: CAS No. 66734-13-2›› 产品链接: CAS No.67452-97-5››