Electroreductive intermolecular coupling of ketones with O-methyl oximes. A convenient route to synthesis of 2-amino alcohols
作者:Tatsuya Shono、Naoki Kise、Taku Fujimoto
DOI:10.1016/s0040-4039(00)79486-x
日期:1991.1
The electroreduction of ketones together with O-methyl oximes gave intermolecularly coupled products, 2-methoxyamino alcohols, which were easily reduced to 2-amino alcohols.
Removable Silyl Group as a “Masked Proton” in Oxy-2-oxonia(azonia)-Cope Rearrangement: Applications in Stereoselective Total Synthesis of Natural Macrolides
In the presence of a Lewis acid, trimethylsilyl-substituted β,γ-unsaturated ketones and aldehydes (imines) undergo nucleophilic addition to produce zwitterionic intermediates, followed by oxy-2-oxonia(azonia)-Cope rearrangements to give homoallylic esters (amides). In the case of TMS-containing 2-vinylcycloalkanones, the process results in ring-enlargement, providing 10- to 16-membered lactones. This
Electroorganic Chemistry. 144. Electroreductive Coupling of Ketones with O-Methyl Oximes, N,N-Dimethylhydrazones, and Nitrones. A Convenient Route to Synthesis of .beta.-Amino Alcohol
The intermolecular coupling of a variety of ketones with some types of O-methyl oximes took place when a mixture of both components was electrochemically reduced in i-PrOH with an Sn cathode. The product, beta-methoxyamino alcohol was easily converted to beta-amino alcohol by simple reduction. A chiral ligand effective for the enantioselective addition of diethylzinc to an aldehyde was easily obtained from the product formed by the electroreductive coupling of (-)-menthone with O-methylacetaldoxime. The intermolecular coupling of a ketone with a N,N-dimethylhydrazone or nitrone was also promoted by the electroreduction. Furthermore, the electroreductive coupling of a carbonyl group with an intramolecular O-methyl oxime moiety gave the corresponding cyclized product stereoselectively.