S. Gronowitz, A. Hallberg, G. Nikitidis
1987
Citations
0
Influential Citations
11
Citations
Journal
Tetrahedron
Abstract
Abstract 2,5-Dimethylthiophene-1,1-dioxide and 3-chloro-2,5-dimethy1-thiophene-1, 1-dioxide react with aqueous piperidine at room temperature in a Michael addition fashion to give respectively 2,5-dimethyl-3-piperidino-trans-2, 3-dihydrothiophene-1,1-dioxide and 3-chloro-2,5-dimethyl-4-piperidino- trans -4, 5-dihydrothiophene-1,1-dioxide in good yields. The reaction of 3-chloro- and 3-bromo-2,5-dimethylthiophene-1, 1-dioxide with piperidine, pyrrolidine and morpholine at 100 °C in toluene on the other hand gave only one of the four possible isomeric dialkylaminomethyl-substituted hatobutadienes as main products and dialkylamino-substituted cis -2,3-dihydrothiophene-1,1-dioxides as by-products. Possible reaction paths are discussed. This useful preparation of dialkylaminomethyl substituted halobutadienes is another example of the synthetic strategy using thiophenes for the regio- and stereospecific syntheses of highly functionalized unsaturated aliphatic compounds. This paper is dedicated to Professor Hans Wynberg on the occasion of his sixty-fifth birthday.