RAYMOND E. DESSU,J. H. II'OTIZ AND C. A. HOLLINGSWORTII
358
washed free of mineral acid and dried, and the solvent was removed. T h e residue was refluxed for one hour with 0.5 g. o f potassium hydroxide in 20 inl. of etli niixlurc, after being cooled and acitlifi with ctlier. The dried ether solution \vas freed o f solvent, leaving a rcd, oily acid residue (0.73 g., Myo),which \vas completely soluble in sodium bicarboilate solution b u t which could not be characterized a t this stage because of its iustability. Oxidation of He1iopsin.-To a stirred suspension of 2.0 g. of heliopsin in 200 ml. of water, maintained at SO", 12.5 g. o f finely powdcred potassium pcrmangaxiate (cquivxlent to 12 moles of oxygen) was added in small portions. ;Is sooii as the reaction rnixturc had become colorless, the manganese dioxide was filtered rind mashed thoroughly with warm water. The combined aqueous filtrates were concentrated down ti) 20 nil. and made acid t o congo red with sulfuric acid. T h e solution was steam distilled t o remove completely the volatile acids and extracted with ether in a continuous extractor for GG hours. The ether solution was freed of solvent, and the partly crystalline residue \vas subjected t o sublimation in :i micro-sublimator. T h e colorless solid subliming a t 10f)-11Oo (15 11ini.) weighed 1.18 g . :ind melted a t 185-186" dLT.
A n d . Calcd. for C?IInO,: neut. equiv., 45. Found: neut. cquiv., 43. The substance (72%, 2.17 moles) was identified as :inhydrous oxalic acid b y a mixture melting point determin:ition with an authentic specimen (m.p. 186-187" dec.). T h e sublimation residue, after recrystallization from ethyl acetate, yielded 0.93 g. of colorless crystals, 111.p. 188189". ;lnnl. Calcd. for C4H,j01: neut. equiv., 59. Found: neut. equiv., 58. The substance was identified as succiuic acid by :i mixture melting point determination, n1.p. 188.0-188.5", a n d by preparation of the di-p-phenylphenacyl ester, n1.p. 208". An additional 190 nig. of succinic acid (total yield 78%,
[COXTRIBUTIOS YO. 980
FROM THE
Yol. 79
1.X moles) was obt:rincd from the ethyl acetate mother liquors, together with :L small amount o f polyinerized material. 1 lie soltiti~~ii ol steaiii-volatile wick olitctiiicd al)ove ~v:is neutr:ilized with sodium hydroxide soluti~m,concentr:ited til a small volunic on the steam-bath, and acidified to congo red with sulfuric acid. The solution was rapidly steam distilled until all material acid t o congo red had distilled over. The distillate was neutralized with sodium liydroxidc solution, the neutral solution was evaporated to dryness, a n d the p-phenylphenacyl ester w:is prepared. I t nieltetl a t 110", and a mixed melting point determination with :iuthentic p-phenylphenncyl :icet:ttc, 1n.p. 1loo, shon.ec1 n o depression. The distillation residue was neutralized with sodium hydroxide solution, concentrated on the steam-bath t o 10 nil., acidified t o congo red with sulfuric acid, and extracted with ether in a continuous extractor. The ether solution dried and freed of solvent. The crystalline residue subli completely at 90-95' (15 mm.), and two recrystallizations from petroleum ether ( b . p . 60-70') gave G42 mg. (73%) o f colorlcss feathery needles, i n .p. 1 0 i o , containing nitrogen. : l m / . C'tlcd. for C,jI111S03: S, 9.(%; neut. equiv., 145. Found: S , 9.63; neut. equiv., IX5. T h e substance wv;ts icienticd with :isynthetic sample of Nisobutyloxamic acid, 1n.p. and mixed m.p. 107'. Exposure of Heliopsin to Ultraviolet Light.-One gram o f heliopsin \vas dissolved in 50 nil. of petroleuin ether (b.1). G0-70°)-ethyl ether (9: 1) and irradiated with an ultraviolet lamp for 3 hours, during which time the solvent evaporated completely. T h e resulting orange viscous oil was taken up in a few milliliters of ether, in which a very small quantity remained insoluble, and the solution was evnporatcd to dryness. T h e viscous yellow oil remaining showed a n infrared spectruni identicnl with that of heliopsin, and w:i$ considered to be unchanged m:itc.ri:il.
,.
BELTSVILLE, MD.
DEPARTMENT O F CHEMISTRY, UNIVERSITY
O F PITTSBURGH]
The Reaction of 1-Alkynes with Organometallic Compounds. VI. of Reactions of Organomagnesium Compounds
The Mechanism
BY RAYMOND E. D E S S UJ. , ~ H. I ~ O TAND I Z C. A. HOLI~INGSWORTH RECEIVEDMAY7. 1956 A mechanism has been postulated for the reaction of Grignard reagents (RMgX) with acetylenes. It is consistent with and R'-C-C-D, with thc the deuterium-isotope effect, measured by comparing the rates of reaction of R'-C=C-H observed rate laws and agrees with previously reported data on the effects of varying R , R ' and X and t h c form of the organomagnesium compound according t o the Schlenk equilibrium. At1 investigation
to be compatible with the formulation of the Grignard reagent proposed by Schlenk
of the reaction 33O
+
R M g X $- R'-C-C-H
ether R'-C-C-LMgS
+ RH
2RMgX (1)
has revealed that the rate of evolution of the hydrocarbon KH is a function of R',3 R and X.4 A correlation also had been noted between the log (reaction rate) and the decomposition potential (Ed) of the Grignard reagent.5 The effect of dioxane upon the rate of reaction 1 has been reported,6and the results have been shown (1) P a r t V , J . OYE.C h e m . , 21, 1003 (1958).
( 2 ) National Science Foundation Predoctoral Fellow. (3) J, 13. Wotiz, C . A . Holl,ngswvorth a n d R. E. Dessy, J . Ore. C h e w . , 2 0 , 1545 (195;). (4) J. I€. Wotiz, C. A . Hollingsworth a n d R. E . Dessy, TFIISJ O U R KAT., 7 7 , 103 (1955). ( 5 ) R.E. Dessy, C . A . Hollingsworth a n d J . H. Wotiz, i b i d . , 7 7 , 4410 ( 19,j.5), ((;) J. TI. Vv'otiz, C
1221 (1!35(\).
A
Jlollinwwrrirth a n d I
