Al[Cl.sub.3].EtOAc was activated during the reaction by the residual water in laccol mixture and carbocation
was formed specifically in the conjugated double bond region of the side chain of catechol ring.
Olah "for his contribution to carbocation
This effect may be associated with the fact that these compounds have substituents at the 2-position of the oxazinic ring, which facilitate the ring-opening process, since furan groups help to stabilize the carbocation
formed at the opening of the oxazinic ring by resonance (Figure 8(b)) .
Ibeanusi, "Density functional theory and mass spectrometry of phthalate fragmentations mechanisms: modeling hyperconjugated carbocation
and radical cation complexes with neutral molecules," Journal of the American Society for Mass Spectrometry, vol.
For such structures, the isomerization reaction is impossible due to instability of the intermediate carbocation
. We have demonstrated that the corresponding 1,3-dioxolanes and 1,3-dioxanes can be obtained via alternative synthetic route based on condensation of monoacetylated butanetriols with paraformaldehyde.
Subsequent cyclization to the carbon radical, Fe(IV) oxidation to the carbocation
, and loss of the C-6 proton yield the vinyl ether, [PGI.sub.2].
Water is a polar solvent, which accelerates many reactions, especially reactions via carbocation
Chemistry: Applications in Organic Synthesis
R133a formation results from defluorination of R-134a followed by chlorination to form the R133a, indicating the presence of a strong reacting agent, likely the presence of methyl radical or methyl carbocation
as the result of dechlorination of the R-40.
He began to investigate these steps more formally about six years ago, eventually unravelling the details of carbocation
For example, in the addition of HBr to buta-1,3-diene, as shown in Scheme III, the resultant mixture of 3-bromobut-1-ene and 1-bromobut-2-ene may be thought of as arising from the addition of Br--to different allylic carbocation