Sample records for cyclopentadiene
from WorldWideScience.org

Sample records 1 - 3 shown.



1

Reações de Diels-Alder entre compostos carbonílicos a,b-insaturados e ciclopentadieno/ Diels-Alder reactions between a,b- insaturated carbonyl compounds and cyclopentadiene

Camilo, Fernanda Ferraz; Gruber, Jonas
1999-06-01

Resumo em inglês We review herewith the use of solids such as activated alumina and other modern Lewis acid catalysts, as well as the influence of different solvents, including water, on the title reactions, described in the last seven years.

Scientific Electronic Library Online (Portuguese)

2

Síntese e avaliação da atividade antimalárica de novos ozonídeos/ Synthesis and evaluation of new ozonides with antimalarial activity

BARBOSA, Luiz Cláudio de Almeida; MALTHA, Célia Regina Álvares; ALVARENGA, Elson Santiago
2002-01-01

Resumo em português A reação de cicloadição [3+4] entre diferentes dienos (ciclopentadieno, 2-metilfurano e furano) e halocetonas levou aos cicloadutos correspondentes, cuja reação de ozonólise forneceu os ozonídeos 3alfa,5alfa-Dimetil-8,9,10-trioxatriciclo[5.2.1.1(2,6)]undecan-4-ona (6), 2,3alfa,5alfa-Trimetil-8,9,10,11-tetraoxatriciclo[5.2.1.1(2,6)]undecan-4-ona (9), 2,3beta,5beta-Trimetil-8,9,10,11-tetraoxatriciclo[5.2.1.1(2,6)]undecan-4-ona (10, isômero exo), 2,3beta,5beta-Trime (mais) til-8,9,10,11-tetraoxatriciclo [5.2.1.1(2,6)]undecan-4-ona (11, isômero endo), 3alfa-Isopropil-8,9,10,11-tetraoxatriciclo[5.2.1.1(2,6)]undecan-4-ona (14). A atividade antimalárica dos ozonídeos foi avaliada em testes "in vitro" contra cepas de Plasmodium falciparum, oriundos da Tailândia. Resumo em inglês Abstract: The [3+4] cycloaddition reaction between different dienes (cyclopentadiene, 2-methylfurane and furane) and haloketones formed their corresponding cycloadducts. Ozonolysis of the cycloadducts yielded the ozonides 3alpha ,5alpha -dimethyl-8,9,10-trioxatricyclo[5.2.1.1(2,6)]undecan-4-one (6), 2,3alpha ,5alpha -trimethyl-8,9,10,11-tetraoxatricyclo[5.2.1.1(2,6)]undecan-4-one (9), 2,3beta ,5beta -trimethyl-8,9,10,11-tetraoxatricyclo[5.2.1.1(2,6)]undecan-4-one (10, exo (mais) isomer), 2,3beta ,5beta -trimethyl-8,9,10,11-tetraoxatricyclo[5.2.1.1(2,6)]undecan-4-one (11, endo isomer), 3alpha -isopropyl-8,9,10,11-tetraoxatricyclo[5.2.1.1(2,6)]undecan-4-one (14). The antimalaria activity of the ozonides was evaluated "in vitro" against strain of Plasmodium falciparum, from Thailand.

Scientific Electronic Library Online (Portuguese)

3

Reatividade em reações de Diels-Alder: uma prática computacional/ Reactivity in Diels-Alder reactions: a computational experiment

Lacerda Júnior, Valdemar; Oliveira, Kleber Thiago de; Silva, Rodrigo Costa e; Constantino, Mauricio Gomes; Silva, Gil Valdo José da
2007-06-01

Resumo em inglês A computational quantum chemistry experiment is described of Diels-Alder reactions between 2-cycloenones and cyclopentadiene. The effects of FMO-Frontier Molecular Orbitals (HOMO-LUMO) and of the withdrawing nature of substituents at the C=C bond of cycloenones were evaluated. The calculations were made using HF/STO-3G and B3LYP/6-31+G(d,p) methods. The FMO based indexes are in agreement with the experimentally observed reactivity order. NBO - Natural Bond Orbitals - analysis was used to ascertain the effect of C=C substituents on the dienophile reactivity.

Scientific Electronic Library Online (Portuguese)