C. M. HILL,L. HAYNES,D.E. SIMMONS AND M. E. HILL [CONTRIBUTION FROM
THE
VOl. 75
DEPARTMENT O F CHEMISTRY, TENNESSEE A. AND I. STATE UNIVERSITY]
Grignard Reagents and Unsaturated Ethers. 11. Reaction of Grignard Reagents with P,y-Unsaturated Ethers' BY CARLM. HILL,LONNIEHAYNES,DORISE. SIMMONS AND MARYE. HILL RECEIVED JUNE 12, 1953 The reactivity of several P,y-unsaturated ethers of the type R-CH=CH-CH~-O-R', where R is H and phenyl and R' is alkyl and phenyl groups, with alkyl and aryl Grignard reagents has been investigated. Reaction products obtained were unsaturated hydrocarbons and alcohols and phenol. The composition and structure of these reaction products indicate that the Grignard reagents cleave the ethers by 1,2- and 1,4addition mechanisms.
Reaction of aryl Grignard reagents with aryl sub- allyl bromide and sodium alkoxide using xylene as solvent.8 Reaction of Allyl Ethers with Grignard Reagents.-All stituted a,@-unsaturated ethyI ethers has been Grignard reagents employed in this investigation were preshown to yield 1,l-diarylethylene compounds and pared and stored under an atmosphere of dry nitrogen. Inethanol.' Luttringhaus, at al., 3 , 4 have indicated asmuch as all experiments were carried out in essentially the that certain aryl allyl ethers and thioethers react same manner, experimental details are described for nallyl ether and n-heptylmagnesium bromide only. with phenyl and alkyl Grignard reagents. Re- cetyl Into a three-neck round-bottomed flask equipped with a cently, Meltzer and King5 during an investigation mechanical stirrer, water cooled condenser set for reflux, and of the structure of methyldihydrothebainone stud- dropping funnel was placed 0.12 mole of n-heptylmagnesium ied the mode of addition of phenylmagnesium bro- bromide (determined by titrations). Twenty-three grams mole) of n-cetyl allyl ether, b.p. 165 (7 mm.), was mide to o-methoxyphenyl crotyl ether. This Labo- (0.082 in an equal volume of anhydrous alcohol-free diratory is engaged in a broad investigation of the dissolved ethyl ether and placed into the dropping funnel. All exits behavior of both aryl and alkyl Grignard reagents to the apparatus were closed by means of calcium chloride toward several types of unsaturated ethers. This tubes. The entire apparatus was flushed with dry nitrogen, and paper describes the reaction of Grignard reagents the reaction mixture was kept under an atmosphere of niwith ane y-substituted allyl ether and several alkyl trogen during the period of the experiment. The ethereal allyl ethers. solution of allyl ether was added dropwise over a period of The results of the present investigation show 4 hr. The reaction mixture was then refluxed for 20 hr., that when n-heptylmagnesium bromide (50% ex- cooled and hydrolyzed with a saturated solution of ammonium chloride containing a few ml. of dilute hydrochloric cess) is allowed to react with n-butyl y-phenyl- acid. The aqueous layer was first shaken with several allyl ether, 3-phenyl-1-decene (52%) and n-butyl small volumes of diethyl ether and then continuously ex,alcohol (76%) are formed. Formation of these tracted for 24 hr. All ether extracts were combined and reaction products can be explained by assuming dried over anhydrous magnesium sulfate. After removal of the diethyl ether, the reaction products and unreacted allyl that the Grignard reagent cleaves the ether by a ether were separated by fractionation through a Todd pre1,4addition mechanism. cision fractionation column.
In experiments with ethylmagnesium bromide and unsaturated ethers, benzene was used as solvent; and the 1pentene was collected in a Dry Ice-methanol-bath attached L to the head of the condenser. CTHls-Mg-X Physical constants and yields of reaction products are C~H~-CH-CH=CHS C~HSOH illustrated in Table I. Identi6cation of Alcohols and Phenol .-Identification of C7Hib the alcohols and phenol was established by comparison of However, the reaction of ethyl-, n-heptyl- and physical constants and preparation of the +nitro- or 3,5dinitrobenzoates. The benzoates were prepared according phenylmagnesium bromides with n-,iso, s- and t- to the procedure of Shriner and Fuson." Physical constants butyl, n-octyl, n-cetyl and phenylallyl ethers gave of the alcohols and phenol and their derivatives are shown the corresponding olefins (14-7393 and alcohols in Table I. Identification of Olefins .-The unsaturated hydrocarbons (1543%) and phenol (60%) expected from the were identified by ozonization and comparison of physical mechanism constants. The ozonization procedure was as follows: Two- to five-gram samples of the olefins (1-decene and 3CHF=CH-CH~-O-R --+ phenyl-1-decene) were dissolved in 50-150 ml. of petroleum .1 ether, and the solution treated with a stream of ozone until R'-Mg-X CHI=CH-CH~-R' f ROH no more was absorbed. This required from 10-24 hr. The solvent was then removed by distillation, and the ozonide treated with an excess of 3% hydrogen peroxide for a period Experimental6 of 24 hr. with intermittent shaking. The hydrogen peroxide Synthesis of Allyl Ethers.-All ethers, except phenyl- solution was made alkaline with 10% sodium hydroxide and allyl,7 were synthesized by condensation of the appropriate extracted with small portions of diethyl ether. During addition of the sodium hydroxide solution, the exit of the ap(1) For the first paper in this series, see C. M. Hill, R. A. Walker paratus was connected to a trap containing a solution of 3 , s and M. E. Hill, THISJOURNAL, 75, 1663 (1951). dinitrophenylhydrazine which reacted with the liberated (2) This research was supported in part by the United States Air formaldehyde. The diethyl ether extracts of the alkaline Farce under Contract AF 18(600)-466 monitored by the Office of solution were dried and the solvent removed. Distillation Scientific Research, HG. Air Research and Development Command. N
CsHaCH=CH--CH2+0--C~H9
+
+
~
(3) A. Ltrttringhaus, G. v. Saaf and K. Hanschild, Bey., 72, 1673 (1938). (4) A. Luttringhaus. G. v. Saaf, E. Sucker and G. Borth, A n n . , 65T, -16 (1947). ( 5 ) R. I. Meltzer and J, A. King, THISJOURNAL, 76, 1.755 (195.7). (0) All melting points are corrected. f7) Piirrhnsrd frctni Aldrich Chwnirnl Cq!., Inc.
( 8 ) E. A. Talky, A. S. Hunter and E. Yanovsky, THISJOURNAL, 18, 3528 (1951). (9) H . Gilman, P. D. Wilkinsnn, W. P. Fishel and C. H. Meyers, i b i d . , 46, 150 (1932). (IO) R. I,. Shriner and I
