Synthesis of new chiral auxiliares from carbohydrates for Et2AlCl-promoted Diels-Alder reactions
Autor(a) principal: | |
---|---|
Data de Publicação: | 2000 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Journal of the Brazilian Chemical Society (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532000000300012 |
Resumo: | Acrylates 3-O-acryloyl-4,5-di-O-benzoyl-1,2- O-isopropylidene-beta-D-fructopyranose (6) and 3-O-benzyl-5-O-acryloyl-1,2-O -isopropylidene-alpha-D-xylofuranose (8) were synthesized in few steps from carbohydrates to construct chiral dienophiles for asymmetric Diels-Alder reaction with cyclopentadiene under thermal and Et2AlCl-promoted conditions. Although from moderate to excellent endo/exo ratios were obtained, low p-facial diastereoselectivities were observed for the cycloadducts 3-O-[(1'R, 4'R)-bicyclo-[2.2.1]hept-2'-ene-5'-formyl]-4,5-di- O-benzoyl-1,2-O-isopropylidene-beta-D-fructopyranose (21a) and 3-O-benzyl-5-O-[(1'S, 4'S)-bicyclo-[2.2.1]hept-2'-ene-5'-formyl]-1,2- O-isopropylideno-alpha-D-yilofuranose (22b) indicating that pi-stacked conformations in the Lewis acid-acrylates complex were not effective. |
id |
SBQ-2_af122026502c6bb13e528469b8a920e0 |
---|---|
oai_identifier_str |
oai:scielo:S0103-50532000000300012 |
network_acronym_str |
SBQ-2 |
network_name_str |
Journal of the Brazilian Chemical Society (Online) |
repository_id_str |
|
spelling |
Synthesis of new chiral auxiliares from carbohydrates for Et2AlCl-promoted Diels-Alder reactionsasymmetric Diels-Alder reactionschiral dienophilescarbohydratesAcrylates 3-O-acryloyl-4,5-di-O-benzoyl-1,2- O-isopropylidene-beta-D-fructopyranose (6) and 3-O-benzyl-5-O-acryloyl-1,2-O -isopropylidene-alpha-D-xylofuranose (8) were synthesized in few steps from carbohydrates to construct chiral dienophiles for asymmetric Diels-Alder reaction with cyclopentadiene under thermal and Et2AlCl-promoted conditions. Although from moderate to excellent endo/exo ratios were obtained, low p-facial diastereoselectivities were observed for the cycloadducts 3-O-[(1'R, 4'R)-bicyclo-[2.2.1]hept-2'-ene-5'-formyl]-4,5-di- O-benzoyl-1,2-O-isopropylidene-beta-D-fructopyranose (21a) and 3-O-benzyl-5-O-[(1'S, 4'S)-bicyclo-[2.2.1]hept-2'-ene-5'-formyl]-1,2- O-isopropylideno-alpha-D-yilofuranose (22b) indicating that pi-stacked conformations in the Lewis acid-acrylates complex were not effective.Sociedade Brasileira de Química2000-06-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532000000300012Journal of the Brazilian Chemical Society v.11 n.3 2000reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50532000000300012info:eu-repo/semantics/openAccessFerreira,Vitor F.Pinheiro,SergioPerrone,Clarissa C.Costa,Paulo R. R.eng2000-11-06T00:00:00Zoai:scielo:S0103-50532000000300012Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2000-11-06T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
Synthesis of new chiral auxiliares from carbohydrates for Et2AlCl-promoted Diels-Alder reactions |
title |
Synthesis of new chiral auxiliares from carbohydrates for Et2AlCl-promoted Diels-Alder reactions |
spellingShingle |
Synthesis of new chiral auxiliares from carbohydrates for Et2AlCl-promoted Diels-Alder reactions Ferreira,Vitor F. asymmetric Diels-Alder reactions chiral dienophiles carbohydrates |
title_short |
Synthesis of new chiral auxiliares from carbohydrates for Et2AlCl-promoted Diels-Alder reactions |
title_full |
Synthesis of new chiral auxiliares from carbohydrates for Et2AlCl-promoted Diels-Alder reactions |
title_fullStr |
Synthesis of new chiral auxiliares from carbohydrates for Et2AlCl-promoted Diels-Alder reactions |
title_full_unstemmed |
Synthesis of new chiral auxiliares from carbohydrates for Et2AlCl-promoted Diels-Alder reactions |
title_sort |
Synthesis of new chiral auxiliares from carbohydrates for Et2AlCl-promoted Diels-Alder reactions |
author |
Ferreira,Vitor F. |
author_facet |
Ferreira,Vitor F. Pinheiro,Sergio Perrone,Clarissa C. Costa,Paulo R. R. |
author_role |
author |
author2 |
Pinheiro,Sergio Perrone,Clarissa C. Costa,Paulo R. R. |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Ferreira,Vitor F. Pinheiro,Sergio Perrone,Clarissa C. Costa,Paulo R. R. |
dc.subject.por.fl_str_mv |
asymmetric Diels-Alder reactions chiral dienophiles carbohydrates |
topic |
asymmetric Diels-Alder reactions chiral dienophiles carbohydrates |
description |
Acrylates 3-O-acryloyl-4,5-di-O-benzoyl-1,2- O-isopropylidene-beta-D-fructopyranose (6) and 3-O-benzyl-5-O-acryloyl-1,2-O -isopropylidene-alpha-D-xylofuranose (8) were synthesized in few steps from carbohydrates to construct chiral dienophiles for asymmetric Diels-Alder reaction with cyclopentadiene under thermal and Et2AlCl-promoted conditions. Although from moderate to excellent endo/exo ratios were obtained, low p-facial diastereoselectivities were observed for the cycloadducts 3-O-[(1'R, 4'R)-bicyclo-[2.2.1]hept-2'-ene-5'-formyl]-4,5-di- O-benzoyl-1,2-O-isopropylidene-beta-D-fructopyranose (21a) and 3-O-benzyl-5-O-[(1'S, 4'S)-bicyclo-[2.2.1]hept-2'-ene-5'-formyl]-1,2- O-isopropylideno-alpha-D-yilofuranose (22b) indicating that pi-stacked conformations in the Lewis acid-acrylates complex were not effective. |
publishDate |
2000 |
dc.date.none.fl_str_mv |
2000-06-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532000000300012 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532000000300012 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0103-50532000000300012 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
Journal of the Brazilian Chemical Society v.11 n.3 2000 reponame:Journal of the Brazilian Chemical Society (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Journal of the Brazilian Chemical Society (Online) |
collection |
Journal of the Brazilian Chemical Society (Online) |
repository.name.fl_str_mv |
Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
||office@jbcs.sbq.org.br |
_version_ |
1750318164127776768 |