Electrooxidative cleavage of carbon-carbon bonds. 2. Double cleavage of .alpha.,.beta.-epoxy alkanones and enantiospecific syntheses of chiral methyl trans- and cis-chrysanthemates from (+)- and (-)-carvones
Electrooxidative cleavage of carbon-carbon bonds. 2. Double cleavage of .alpha.,.beta.-epoxy alkanones and enantiospecific syntheses of chiral methyl trans- and cis-chrysanthemates from (+)- and (-)-carvones
Lewis acid-catalyzed oxidative rearrangement of tertiary allylic alcohols mediated by TEMPO
作者:Jean-Michel Vatèle
DOI:10.1016/j.tet.2009.11.104
日期:2010.1
Two methods for the oxidative rearrangement of tertiary allylic alcohols have been developed. Most of tertiary allylic alcohols studied were oxidized to their corresponding transposed carbonyl derivatives in excellent to fair yields by reaction with TEMPO in combination with PhIO and Bi(OTf)3 or copper (II) chloride in the presence or not of oxygen. Other primary oxidants of TEMPO such as PhI(OAc)2
Copper-Catalyzed Aerobic Oxidative Rearrangement of Tertiary Allylic Alcohols Mediated by TEMPO
作者:Jean-Michel Vatèle
DOI:10.1055/s-0029-1217545
日期:2009.8
A mild method for the oxidativerearrangement of tertiary allylic alcohols to β-substituted enones using a TEMPO/CuCl 2 system, in the presence of molecular sieves, is described. Depending on the substrate, CuCl 2 was used in either a catalytic amount under an oxygen atmosphere or stoichiometrically.
Novel pyridinium dichromate (PDC) catalyzed oxidative rearrangement for the conversion of tertiary allylic alcohols to ß-substituted enones is described. Using a catalytic amount of PDC with PhI(OAc)2 as a co-oxidant in the presence of magnesium sulfate and water under oxygen was found effective for this rearrangement.