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On the Ring-Opening Reaction of Thiophene-1,1-dioxides and the Intramolecular Diels-Alder Reaction of Azanona- and AzadecatrienesI

Tsirk, Anders Sebastian LU (1997)
Abstract
Substituted thiophene-1,1-dioxides were synthesized and their ring-opening reactions with omega-unsaturated secondary amines were investigated; this led to a synthetic route to azatrienes and to the preparation of some polyhydroisoindoles and polyhydroisoquinolines via an intramolecular Diels-Alder reaction. By using 2-substituted pyrrolidines and piperidines various tetrahydrobenzo[f]indolizidines, benzo[b]quinolizidines, tetrahydrobenzo[a]indolizidines and tetrahydro[a]pyrrolizidines could be synthesized via the ring-opening of 3-bromo-2,5-dimmethylthiophene-1,1-dioxide and a subsequent intramolecular Diels-Alder reaction. Aminoalcohols such as L-prolinol worked well and a diastereo- selective synthesis of substituted... (More)
Substituted thiophene-1,1-dioxides were synthesized and their ring-opening reactions with omega-unsaturated secondary amines were investigated; this led to a synthetic route to azatrienes and to the preparation of some polyhydroisoindoles and polyhydroisoquinolines via an intramolecular Diels-Alder reaction. By using 2-substituted pyrrolidines and piperidines various tetrahydrobenzo[f]indolizidines, benzo[b]quinolizidines, tetrahydrobenzo[a]indolizidines and tetrahydro[a]pyrrolizidines could be synthesized via the ring-opening of 3-bromo-2,5-dimmethylthiophene-1,1-dioxide and a subsequent intramolecular Diels-Alder reaction. Aminoalcohols such as L-prolinol worked well and a diastereo- selective synthesis of substituted tetrahydro[a]pyrrolizidines was achieved. Asymmetric induction was observed in the L-prolinol induced ring-opening of 3-bromo-5-ethyl-2-isopropylthiophene-1,1- dioxide. A multivariate optimization procedure involving the use of response surface methodologies was undertaken to improve yields in the ring-opening reaction of 2-alkyl-3-bromo-5-methylthiophene- 1,1-dioxides. The mechanism of the ring-opening reaction was studied by isotope labeling and measure- ments of kinetic isotope effects. Semiempirical and ab initio calculations were made on transition states in order to explain stereoselectivities of the intramolecular Diels-Alder reaction in the azanona- and aza- decatriene series. (Less)
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author
opponent
  • Docent Somfai, Peter, Organic Chemistry 2, P.O. Box 124, 221 00 Lund
organization
publishing date
type
Thesis
publication status
published
subject
keywords
transition states, 3-21G(*), intramolecular Diels-Alder reactions, asymmetric induction, multivariate optimization, kinetic isotope effects, rearrangements, secondary amines, 1-dioxides, Ring-opening reaction, thiophene-1, stereoselectivity., Organic chemistry, Organisk kemi
pages
179 pages
defense location
lecture hall D, Chemical Center
defense date
1997-09-26 10:15
external identifiers
  • Other:ISRN: LUNDL/NKOK-1037-SE
ISBN
91-628-2639-5
language
English
LU publication?
yes
id
f4dd8f5d-064c-46fd-af64-d820b73715cf (old id 29517)
date added to LUP
2007-06-12 16:32:06
date last changed
2016-09-19 08:45:16
@misc{f4dd8f5d-064c-46fd-af64-d820b73715cf,
  abstract     = {Substituted thiophene-1,1-dioxides were synthesized and their ring-opening reactions with omega-unsaturated secondary amines were investigated; this led to a synthetic route to azatrienes and to the preparation of some polyhydroisoindoles and polyhydroisoquinolines via an intramolecular Diels-Alder reaction. By using 2-substituted pyrrolidines and piperidines various tetrahydrobenzo[f]indolizidines, benzo[b]quinolizidines, tetrahydrobenzo[a]indolizidines and tetrahydro[a]pyrrolizidines could be synthesized via the ring-opening of 3-bromo-2,5-dimmethylthiophene-1,1-dioxide and a subsequent intramolecular Diels-Alder reaction. Aminoalcohols such as L-prolinol worked well and a diastereo- selective synthesis of substituted tetrahydro[a]pyrrolizidines was achieved. Asymmetric induction was observed in the L-prolinol induced ring-opening of 3-bromo-5-ethyl-2-isopropylthiophene-1,1- dioxide. A multivariate optimization procedure involving the use of response surface methodologies was undertaken to improve yields in the ring-opening reaction of 2-alkyl-3-bromo-5-methylthiophene- 1,1-dioxides. The mechanism of the ring-opening reaction was studied by isotope labeling and measure- ments of kinetic isotope effects. Semiempirical and ab initio calculations were made on transition states in order to explain stereoselectivities of the intramolecular Diels-Alder reaction in the azanona- and aza- decatriene series.},
  author       = {Tsirk, Anders Sebastian},
  isbn         = {91-628-2639-5},
  keyword      = {transition states,3-21G(*),intramolecular Diels-Alder reactions,asymmetric induction,multivariate optimization,kinetic isotope effects,rearrangements,secondary amines,1-dioxides,Ring-opening reaction,thiophene-1,stereoselectivity.,Organic chemistry,Organisk kemi},
  language     = {eng},
  pages        = {179},
  title        = {On the Ring-Opening Reaction of Thiophene-1,1-dioxides and the Intramolecular Diels-Alder Reaction of Azanona- and AzadecatrienesI},
  year         = {1997},
}