The Jacobsen Rearrangement of 6-Methyl-7-propyltetralin¹

Abstract

The yields and purity of the crude disulfides were determined by weight and analytical method^.^^' Their disulfide and thiol contents were determined and the results are shown in Table I, along with melting points of the crude and purified disulfides.Oxidation of Benzenethio1.-Two-tenths of a mole of benzenethiol was dissolved in 100 ml. of dimethyl sulfoxide and the solution was maintained a t 85 f l o . Samples were removed a t various intervals and analyzed for thiol and disulfide content.617The following conversions of thiol to disulfide were found: 85Y0 after 30 min., 92.47, after 1 hr., 96.77, after 2 hr., 98.3% after 4 hr., and 98.9y0 after 6 hr.Oxidation of Benzenethiol in the Absence of Air .-A 250-ml. three-necked flask was equipped with a magnetic stirrer, thermometer, a nitrogen gas inlet tube, and an outlet to a trap cooled in Dry Ice. The flask was charged with 11 g. (0.1 mole) of benzenethiol and 50 ml. of dimethyl sulfoxide under a blanket of nitrogen and the solution was heated with stirring a t 80" for 18 hr. with a continuous flow of nitrogen through the system. The disulfide isolated in almost theoretical yield by procedure A weighed 10.8 g. and melted a t 61-62",The liquid condensed in the Dry Ice trap separated in two layers. The upper one proved to be the expected dimethyl sulfide by infrared spectrum and boiling point; the lower layer was mainly water.Similar results were obtained when the experiment was carried out with a-toluenethiol with the by-products being identified as dimethyl sulfide and water. The disulfide was obtained in 88% yield with m.p. 71-72".

2,4‐Dioxabicyclo‐[3.3.1]‐Nonane. A Distorted Chair form Having a Non‐Classical Long Range Coupling VII. Long Range Phenomena [1]

“…I]-nonane have appeared already [3], but the lack of multiple resonance experiments throws doubt upon the correctness of the interpretation. These authors [3] came to the conclusion that the compound (VII) has mainly a double chair conformation. The only serious arguments comes from the observation of an 1.R active band at 2996cm-', which may be explained by a possible "proximity" effect and a serious steric hindrance for certain C-H bonds.…”