Understanding reactivity and regioselectivity in Diels–Alder reactions of a sugar-derived dienophile bearing two competing EWGs. An experimental and computational study
作者:Germán F. Giri、Ariel M. Sarotti、Rolando A. Spanevello
DOI:10.1016/j.carres.2015.07.017
日期:2015.10
The effect of an extra EWG in the reactivity and regioselectivity in Diels-Alderreactions of beta-cyanolevoglucosenone and 4 different dienes was studied by a joint computational and experimental study. Conceptual DFT analysis successfully predicted an important enhancement in the reactivity, and correctly anticipated the regioselectivity in the reactions with isoprene. However, this static treatment
Assessing the halogen effect in Diels–Alder reactions involving chiral α-halo enones. A combined experimental and DFT computational approach
作者:Ariel M. Sarotti、Rolando A. Spanevello、Alejandra G. Suárez
DOI:10.1016/j.tetlet.2011.05.143
日期:2011.8
experimental and computational study was conducted to assess the effect of chlorine and bromine substitution in Diels–Alderreactions involving chiral α-halo enones as dienophiles. An important rate enhancement was observed in the case of acyclic dienes, while the use of cyclic dienes resulted in prolonged reaction times and lower yields. DFT calculations suggest that these reactions are governed by finely
DFT calculations induced a regiochemical outcome revision of the Diels–Alder reaction between levoglucosenone and isoprene
作者:Ariel M. Sarotti、Alejandra G. Suárez、Rolando A. Spanevello
DOI:10.1016/j.tetlet.2011.04.021
日期:2011.6
An appealing inversion in the regiochemical outcome of Diels–Alderreactions between levoglucosenone (1) and its α-bromo derivative (5) with isoprene (2) was studied computationally. Based on different DFT calculations we concluded that both reactions should display the same regioselectivity. This result was further validated experimentally.
Reactions of stereocontrolled intramolecular carbocyclization of levoglucosenone adduct with isoprene
作者:B. T. Sharipov、O. Yu. Krasnoslobodtseva、L. V. Spirikhin、F. A. Valeev
DOI:10.1134/s1070428010020144
日期:2010.2
An intramolecular carbocyclization was found of levoglucosenone adduct with isoprene providing a fused cyclobutane. The intramolecular oxacyclization of the adduct was performed under the treatment with I(2), H(3)PO(4), SOCl(2), and Pd/C leading to 1,4-epoxide. Methods were developed of radical and anionic (by Ferrier method) transformation of the adduct into chiral trans- and cis-decalins.