The transition-states of rearrangement reaction of the stable structure of F 2CCLiBr have been determined, and the potential barriers of rearrangement reactions have been obtained at B3LYP/6-31G(d,p) level. 对稳定的平衡结构 ,找到了其可能的重排反应过渡态 ,根据计算得到的重排反应势垒 ,解释了氟...
An enzymatic example of an acyloin rearrangement is the reaction catalyzed by acetohydroxy acid isomeroreductase in the biosynthesis of valine and isoleucine; the same enzyme catalyzes transformations of both acetolactate (13.32) and α-aceto-α-hydroxybutyrate (13.34) to give α,β-dihydroxyisovalerate...
Dinitration of 2,4,5-tribromo-3,6-dimethylphenol(1) gives either the tribromodinitro-compound(2) or its acyloin rearrangement product(3), depending on the reaction conditions: X-ray crystal structure analyses are reported for compounds (2) and (3).P.A. Bates and E.J. Ditzel and M.P...
Both dimethylphenyl- and methyldiphenylsilyllithium were found to be effective, the latter providing greater stereocontrol. The reaction is believed to proceed via Brook rearrangement assisted by expulsion of the adjacent leaving group. A number of acyclic acyloin derivatives were reacted to form the ...
In this Letter, we describe an easy and straightforward strategy for the preparation of acyloins (α-hydroxyketones) from Morita–Baylis–Hillman adducts, based on a Curtius rearrangement. Different acyloins were obtained with good overall yield (>40% for three steps). To exemplify the synthetic...
In earlier papers 2*3 we reported a rearrangement aimed at the synthesis of 4P-demethyllanosterol. Thus, the acid-catalysed reaction of x-hydroxy dithioacetals, derivatives of 3-acetyl-3- hydroxy-14x-methyl-4-nor-5a- and -SP-cholest-S-ene, resulted in the exclusive migration of a ...
The relatively low temperature (200°C) intramolecular ene reaction of 4,5-seco-5β-cholest-3-en-5-ol-6-one followed by in situ rearrangement affords 3-methl-B-nor-5β-cholest-2-en-4-one and 5-hydroxy-5β-cholestan-6-one and supports the view that 3β-methyl-A-nor-5β-cholestan...
The reaction is believed to proceed via Brook rearrangement assisted by expulsion of the adjacent leaving group. A number of acyclic acyloin derivatives were reacted to form the corresponding silyl enol ethers in good to excellent yield.doi:10.1016/j.tetlet.2008.01.133Bradley D. Robertson...