Catalytic Rearrangement of O-Cholesteryl S-Alkyl Dithiocarbonates to S-Alkyl S-Cholesteryl Dithiocarbonates by Phenols
Phenolysis of O-cholesteryl S-alkyl dithiocarbonates gave the corresponding S-alkyl S-cholesteryl dithiocarbonates.The rearrangements obeyed first-order rate laws and the rates were affected by the acidity of the phenols.A plot of the substituent effect of the S-alkyl moiety against the Tafts ?* values was roughly linear. ortho-Substituted phenols such as 2-chlorophenol or 2,6-dimethylphenol considerably retarted the rearrangement.The role of phenols and the reaction behavior of O-cholesteryl S-alkyl dithiocarbonates are discussed on the basis of kinetic and molecular orbital calculation data indicating that the rearrangement may proceed by specific solvation of phenols at the thiocarbonyl sulfur atom.Keywords: O-cholesteryl S-alkyl dithiocarbonate; homoallylic participation; phenol-catalyzed rearrangement; S-cholesteryl S-alkyl dithiocarbonate; hydrogen bonding; phenolysis; frontier molecular orbital; reaction rate
Get Best Price for99613-47-5Dithiocarbonic acid S-[(1aS,3aR,3bS,5aR,6R,8aS,8bS,10R,10aS)-6-((R)-1,5-dimethyl-hexyl)-3a,5a-dimethyl-hexadecahydro-cyclopenta[a]cyclopropa[2,3]cyclopenta[1,2-f]naphthalen-10-yl] ester S-methyl ester