June, 1934
COMMUNICATIONS TO THE EDITOR
derivatives of a cyclopentenophenanthene ring system like the sterols and the bile acids.
1425
1243 (1934)l and unpublished work on the addition of hydrogen bromide to pentene-1 are aIso FROMTHE LABORA.TORIES OF WALTER A. JACOBS completely in accord with our earlier observaTHE ROCKEFELLER INSTITUTE JAMESC . E. SIMPSON tions. Finally, in view of the possibility of interFOR MEDICAL RESEARCH Commonwealth Fund Fellow preting the work of Whitmore and Homeyer NEWYORKCITY RECEIVED MAY5, 1934 [ibid., 55, 4555 (1933)l as in disagreement with our observations, we would say that Professor Whitmore in a private communication assures THE PEROXIDE EFFECT IN THE ADDITION OF us that he has confirmed our recent findings as to REAGENTS TO UNSATURATED COMPOUNDS the effects of peroxides and antioxidants in the Sir: addition of hydrogen. bromide to 4,4-dimethylOn the basis of a study of the addition of hydro- pentene-1 [Kharasch, Hannum and Gladstone, gen bromide to pentene-1 and heptene-1 in glacial ibid., 56, 244 (1934)l. Professor Whitmore has acetic acid, hexane and water, Sherrill; Mayer and generously withheld publication of his note in Walter [THIS JOURNAL, 56, 926 (1934)] conclude order to accord us priority. that the solvent is the dominant factor governing JONESCHEMICAL LABORATORY M. S. KHARASCH OF CHICAGO M. C . MCNAB the direction of addition, and that the peroxide UNIVERSITY CHICAGO, ILLINOIS effect is insignificant or non-existent. They ignore RECEIVED MAY7, 1934 the work of Kharasch, McNab and Mayo on the addition of hydrogen bromide to vinyl chloride, allyl and vinyl bromides and reject their work on THE ACTION OF THE GRIGNARD REAGENT ON a#-UNSATURATED ALDEHYDES the addition of hydrogen bromide to propylene on Sir: the ground that the small quantities of materials employed furnish yields which are “not very Up to the present time the reaction of the significant” [Kharasch and Mayo, THISJOURNAL, Grignard reagent with a,@-unsaturatedaldehydes 55, 2468 (1933); Kharasch, McNab and Mayo, has been considered as taking place solely through ibid., 55, 2521 (1933); 55, 2131 (.1933)]. the carbonyl group, e. g., 1,2-addition. It has We have now repeated our earlier study of the now been found that t-butylmagnesium chloride addition of hydrogen bromide to propylene using reacts with crotonic aldehyde yielding both 1,2larger quantities of reagents. Identification of and 1,4-addition products in about equal amount the products was made by boiling points, refrac- (about 25%). Moreover, preliminary experitive indices and the preparation of mercury ments with ethyl-, propyl- and isopropylmagnederivatives. Using 1.4 mol (85 g.) of hydrogen sium bromides and crotonic aldehyde indicate that bromide, 1 mol (31.5 g.) of propylene and 2 g. here, too, some 1,4-addition takes place though to of ascaridole as peroxide or antioxidant we ob- a very much less extent. tained, working a t -go’, both without a solvent The aldehyde, CBH160,semicarbazone: m. p. and using glacial acetic acid, an 80% yield of 166’, arising from t-butylmagnesium chloride and 100% n-propyl bromide, b. p. 70-71’, ng crotonic aldehyde was easily oxidized by Tollens’ 1.4340, and with a mercury derivative melting at solution to an acid, CsHle02, amide: m. p. 137.2’. With carbon tetrachloride as a solvent 163-4’. Bromination of this acid by the Hell, an IS% yield was obtained. Similar experiments Volhard and Zelinsky method followed by using 2 g. of diphenylamine as peroxide or anti- treatment with methyl alcohol led to an a-bromo oxidant gave, with no solvent, or glacial acetic ester, C9H1702Br,which when heated with diacid or carbon tetrachloride, respectively, 61, 65 ethylaniline yielded an a,P-unsaturated ester, and 44% yields of 100% isopropyl bromide, b. p. C9HI6O2. Ozonolysis of this ester produced 59-60’, &’ 1.4250 (*O.OOOl) and a mercury pinacolone identified as the semicarbazone: m. p. derivative melting at 92.6’. These results con- 155’. The original aldehyde was therefore iirm our earlier observations and conclusions in p, y,y-trimethylvaleric aldehyde. every detail. THERESEARCH LABORATORY OF ORGANIC CHEMISTRY INSTITUTE OF TECHNOLOGY We would also point out that recently pub- MASSACHUSETTS CONTRIBUTION No. 111 lished work on butene-1 and isobutylene [Khar- CAi%BRIDGE, MASS. PHILIPG . STEVENS asch and Hincldey, Jr., THISJOURNAL, 56, 1212, RECEIVED MAY17, 1934
