THE SYNTHESIS OF NEOPENTHYL NITROPARAFFINS AND THEIR CONVERSION TO ALDEHYDES
Abstract
The replacement of an aliphatic tertiary nitro group by nitromethyl and subsequent conversion of the nitromethyl group to an aldehyde is described. The first step of this synthesis proceeds in yields of 60-96% with most yields being greater than 85%. This reaction tolerates the presence of other functional groups including nitriles, acetals, trifluoromethyl, t-butyl esters and sulfones. The fact that this reaction succeeds with tertiary nitroparaffins in which the intermediate radical is not stabilized by other functional groups is of particular interest since this is the first instance in which the tertiary nitro group of such nitroparaffins has been replaced with the formation of a carbon-carbon bond. Evidence is presented which clearly supports the view that substitution of nitro by nitromethyl proceeds via radical anions. On this basis, the ability of sodium hydride to induce these reactions becomes readily intelligible since dimsyl anion, produced by the action of sodium hydride on DMSO, is a well-known one-electron transfer agent. The second part of this synthesis, the conversion of the nitromethyl group to an aldehyde, was accomplished by oxidizing the nitroparaffin salt with aqueous potassium permanganate. Yields of 80-95% were obtained when the oxidation was carried out in a vigorously stirred aqueous system containing a water immiscible organic solvent. All the aldehydes so produced have the aldehyde group on a quaternary carbon. In a single case, the salt of a straight chain primary nitroparaffin (1-nitrodecane) was oxidized to the corresponding pure aldehyde (decanal) in 81% yield. In addition, a simple procedure for converting primary nitroparaffins to their mono chloro, bromo or iodo derivatives in yields ranging from 81-93% was devised. Preliminary studies concerned with the conversion of primary mono halonitroparaffins to symmetrical vicinal dinitroolefins are described; yields up to 70% have already been obtained.
Degree
Ph.D.
Subject Area
Organic chemistry
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