Synthesis and properties of some 2,5-dihydrothiophene 1,1-dioxides

The chemical properties of 3-methyl-2, 5-dihydrothiophene 1, 1-dioxide have been studied including ionic additions, radical initiated reactions, Diels-Alder reactions, ietalation, condensation, and oxidation and reduction reactions.

For the first time the introduction of one halogen atom into the unsaturated five-membered cyclic sulfone without the isomerization of the double bond was accomplished.

The properties of 3-bromomethyl-2, 5-dihydrothiophene 1, 1-dioxide have been investigated including displacement reactions, allylic rearrangement, Diels- Alder reaction, pyrolysis and salt formation.

A synthesis of conjugated, substituted dienes was illustrated by the synthesis of 2-bromomethyl- 1,3-butadiene.

A novel Diels-Alder reaction between 3-bromomethyl and 2,5-dihydrothiophene 1, 1-dioxide has been described.

The structure of 3-bromomethyl-2, 5-dihydrothiophene 1, 1-dioxide was supported both by pyrolysis studies and by the above mentioned Diels-Alder reaction. The structure of the pyrolysate, 2-bromomethyl- 1,3-butadiene, was substantiated by both infrared and ultraviolet evidence.

Isomeric monobromo dihydrothiophene 1, 1-dioxides have been prepared via elimination reactions of the isomeric dibromo tetrahydrothiophene 1, 1-dioxides. Their structures have been supported by ultraviolet absorption studies.

Evidence for the allylic rearrangement of 3-bromomethyl-2, 5-dihydrothiophene 1, 1-dioxide was achieved through ultraviolet absorption studies.

A simple method for the identification of alkyldinydrothiophene 1, 1-dioxides was demonstrated.

The modified Prilezhaev oxidation has been applied to 3-methyl-2,5-dihydrothiophene 1, 1-dioxide.

The addition of chlorine and of hydrogen iodide to 3-methyl-2,5-dihydrothiophene 1, 1-dioxide was accomplished.

The formation of the quaternary salts from 3-bromnomethyl-2, 5-dihydrothiophene 1, 1-dioxide and nitrogenous bases was found to be of general application. The use of certain salts as synthetic intermediates was attempted.