Studies on cycloaddition reactions of 2,2-dimethyl-3,4-dihydro-2H-pyrrole N-oxide and N-(benzylidene)methylamine N-oxide with alpha,beta-unsaturated lactones esters

Intermolecular asymmetric 1,3-dipolar cycloaddition of 2,2-dimethyl-3,4-dihydro-2H- pyrrole N-oxide and N-(benzylidene)methylamine N-oxide with optically active alpha,beta-unsaturated esters 1,2,4 and 7-9 provided the corresponding diastereomers while chiral sugar lactones gave stereoselectively the...

Full description

Saved in:
Bibliographic Details
Published inTetrahedron Vol. 53; no. 20; pp. 7057 - 7076
Main Authors Baskaran, S, Baskaran, C, Nadkarni, PJ, Trivedi, GK, Chandrasekhar, J
Format Journal Article
LanguageEnglish
Published OXFORD Elsevier 19.05.1997
Subjects
Chemistry
Chemistry, Organic
Physical Sciences
Science & Technology
REACTIVITY
1-OXIDE
1,3-DIPOLAR CYCLOADDITIONS
NITRONES
CYCLO-ADDITIONS
SELECTIVITY
Online AccessGet full text

Cover

More Information
Summary:Intermolecular asymmetric 1,3-dipolar cycloaddition of 2,2-dimethyl-3,4-dihydro-2H- pyrrole N-oxide and N-(benzylidene)methylamine N-oxide with optically active alpha,beta-unsaturated esters 1,2,4 and 7-9 provided the corresponding diastereomers while chiral sugar lactones gave stereoselectively the cycloadducts 17a and 17b (in the case of dipolarophile 3) and 18 in (the case of the dipolarophile 6) with the acyclic nitrone B. The stereochemistry of the products has been established using high field nmr techniques. The regioselectivities of these reactions are inconsistent with FMO coefficients and are explained on the basis of charge distribution obtained through AM1 calculations. (C) 1997 Elsevier Science Ltd.
ISSN:0040-4020
DOI:10.1016/S0040-4020(97)00403-1