摘要:
A novel single-pot trialkylsilyl trifluoromethanesulfonate (R.sub.3 Si-OTf) mediated process produces derivatives of 4-aza 3-keto steroids at the .alpha.-methylenic carbon through electrophilic substitution. These derivatives are useful in the preparation, through elimination of the substituent on the .alpha.-methylene carbon, of .DELTA.-1 olefin 4-aza 3-keto steroids which are potent inhibitors of 5-.alpha. reductase.
摘要:
A novel, facile, and specific process for .alpha.-iodinating or .alpha.-brominating the .alpha.-methylenic carbon of a straight chain, branched chain, or cyclic secondary amide, such as a lactam or an azasteroid, comprises reacting the amide with trialkylsilyl-X (R.sub.3 Si--X), where X is Br, I, or Cl, and R is methyl, ethyl, or n-propyl, in the presence of I.sub.2 or Br.sub.2. The .alpha.-iodo- or .alpha.-bromo-amide is useful for making the .alpha.,.beta.-unsaturated amide through dehydrohalogenation.
摘要:
A novel single-pot trialkylsilyl trifluoromethanesulfonate (R.sub.3 Si--OTf) mediated process produces derivatives of 4-aza 3-keto steroids at the .alpha.-methylenic carbon through electrophilic substitution. These derivatives are useful in the preparation, through elimination of the substituent on the .alpha.-methylene carbon, of .DELTA.-1 olefin 4-aza 3-keto steroids which are potent inhibitors of 5-.alpha. reductase.
摘要:
This invention relates to a process for preparing .beta.-lactams by electrochemically deblocking N-substituting .beta.-lactams using anodic oxidation.
摘要:
A process for the preparation of (S)- or L-3-(3,4-dihydroxyphenyl)alanine (L-dopa) is described. The process utilizes water as reaction process solvent and proceeds via formation of an intermediate which can be kinetically resolved in a polar solvent to a precursor of the desired isomer and in which the undesired isomer can be efficiently racemized for reuse.