TY - JOUR

T1 - 1,3-Dipolar cycloaddition reactions of ylides formed from pyridines and dichlorocarbene

AU - Khlebnikov, A. F.

AU - Kostik, E. I.

AU - Kostikov, R. R.

AU - Bespalov, V. Ya

PY - 1990/3/1

Y1 - 1990/3/1

N2 - Pyridinium dichloromethylides, generated from substituted pyridines and dichlorocarbene, react endo-stereoselectively with dimethyl maleate to give substituted 3,3-dichloro-1,2,3,8a-tetrahydroindolizine-1,2-dicarboxylic acid dimethyl esters; the latter compounds are readily dehydrochlorinated and dehydrogenated to give the corresponding indolizine derivatives. Reaction of 3-substituted pyridines with dichlorocarbene and dimethyl maleate leads predominantly to the formation of 8-substituted indolizines. Cycloaddition of 4-picolinium dichloromethylide to unsymmetrical dipolarophiles occurs regioselectively. The observed selectivity in these reactions is consistent with predictions made on the basis of PMO theory.

AB - Pyridinium dichloromethylides, generated from substituted pyridines and dichlorocarbene, react endo-stereoselectively with dimethyl maleate to give substituted 3,3-dichloro-1,2,3,8a-tetrahydroindolizine-1,2-dicarboxylic acid dimethyl esters; the latter compounds are readily dehydrochlorinated and dehydrogenated to give the corresponding indolizine derivatives. Reaction of 3-substituted pyridines with dichlorocarbene and dimethyl maleate leads predominantly to the formation of 8-substituted indolizines. Cycloaddition of 4-picolinium dichloromethylide to unsymmetrical dipolarophiles occurs regioselectively. The observed selectivity in these reactions is consistent with predictions made on the basis of PMO theory.

UR - http://www.scopus.com/inward/record.url?scp=34249959653&partnerID=8YFLogxK

U2 - 10.1007/BF00472551

DO - 10.1007/BF00472551

M3 - Article

AN - SCOPUS:34249959653

VL - 26

SP - 304

EP - 311

JO - Chemistry of Heterocyclic Compounds

JF - Chemistry of Heterocyclic Compounds

SN - 0009-3122

IS - 3

ER -