4976
A. T. BLOMQUIST, J. IT^^^^^, C. L. AD.%MI,J. ~TOLINSKY AND D. D. PHILLIPS
ethyl ether a t room temperature using Adams catalyst gave S.S g. of 3-ethyl-l-pentano1, b.p. 90-91.5" (30 mm.), n% 1.4287, d2'4 0.8398. Anal. Calcd. for C7H160: C, 72.35; H, 13.88; MRD, 36.1. Found: C, 72.03, 72.37; H, 14.10, 14.20; M R D , 33.6. Oxidation of 2.8 g. of 3-ethyl-l-l)cnti~tolby tlie method of Fourilier25 gave 1.04 g. of 3-cthyl-l-pentanoic acid, b.p. 207-208.5" (reportedzGfor 3-ethyl-1-pentanoic acid, b.p. ( 2 5 ) Fournier, Bull. soc. c h i m France, [41 5 , 920 (1909). (26) P. Fichter, .4.Riefer and W. Bernoulli, Buy., 42, 4713 (1909).
[CONTRII3UTION FROM THE
VOl. '79
212'. The amide was obtained as flaky plates from ethanol; 111.p. 138.5-199.5" (reported2' m.p. 127.5'). The pipcrazonium salt prepared by the method of Pollard2* showed 1n.p. 133-134' (reportedzgm.p. 133-134'). (27) F.Bayer and Co., German Patent 223,809; Chero. Zciztr., 8 1 , 11, 254 (1910). (28) C. B. Pollard, D. 13. Adelson and J . P. Bain, 'TILLS J O I I K N A56, I~, 1759 (1934). (20) S. G . Powell and M. M. Baldwin, ibid., 58, 1x72 ( I 9 X ) .
ITIIACA, N. Y .
BAKERLABORATORY O F CIIEMISTRY AT
CORNELL UNIVERSITY]
Thermal Condensation of Cyclic Olefins with Formaldehyde'j2 BY 9. T. BIAMQUIST, JOSEPH
vERDOL,3 C L A I R E
L. ADAMI,
JOSEPH w O L I N S K Y 3 AND
DONALD D.
PHILLIPS
RECEIVED MARCH30, 1957 Thermal condensation of formaldehyde with cycliihexcrie, pure a-pinene, d-limonene and 1-methylcyclohexene either in the presence of solvent acetic acid-acetic anhydride or in the absence of solvent affords, respectively, as principal products "homolimonenol," and an 2-cyclohexenemethanol acetate, 2-methylenc-6,0-tlimethylbicyclo[3.3.l]heptane-3-methanol, approximately equal mixture of 2-acetoxymethylmethylenecyclohexane and 3-acetoxymethyl-2-methylcyclohexene. T h e formation of these products is in accord with a postulation that suggests a planar six-membered ring for the transition state of the reaction.
h recent article presented our observations on acetate of 2-cyclohexenemethannl (I) in ca. 10% the behavior of representative acyclic olefins in yield together with a small amount of higher boiling their thermal Condensation with formaldehyde.* material.' Although I has not been described preIt seemed desirable to extend this study by examA/CHzOH ining also the thermal condensation of snme typical cyclic olefins with formaldehyde. There was special interest in the behavior of a-pinene, d-limonene and I ; Ia, tlie acetate cyclohexene as these olefins have been reported to be essentially unreactive in the c ~ n d e n s a t i o n . ~ -viously ~ all of its pertinent isomers have been reOn the basis of our earlier work with the acyclic ported. The properties of I and three of its crystalolefins2 such cyclic olefins would be expected to be line derivatives did not correspond to those rereactive albeit to perhaps a lesser extent. We have ported for l-cyclohexenemethanol,s 4-cyclohexenefound, in fact, that the olefins cyclohexene, l-meth- methanol, 9,10 2-methylenecyclohexano18~ and 2ylcyclohexene, a-pinene and d-limonene do react methyl-l-cyclohexene-3-01.~~~*~ A tetrahydrobenwith formaldehyde to afford monocondensation zyl alcohol whose phenylurethan derivative showed products to the extent of 10-5470. m.p. 63', was reported by Pommereau.15 This may The condensations with paraformaldehyde were have been I as the phenylurethan derivative of our carried out either in the presence or absence of I showed m.p. 61-63'. The infrared absorption solvent acetic acid-acetic anhydride at tempera- spectrum of I showed maxima a t 13.83, 14.40 and tures varying from 160-1SOo. The principal 14.50 p which are observed for %methyl and 3products obtained were primary unsaturated alco- methyl-1-cyclohexene, etc.,l6 and appear to bc hols or their acetates in which the double bond oc- characteristic of an unsubstituted carbocyclic cupied a position adjacent to that in the starting ( 7 ) T h e mixture contained trans-2-hydroxymethyl-1-cyclohexan~l cyclic olefin. diacetate (11) a n d possibly t h e diacetates of 1,3-bis-(hydroxymethyl)The condensation of cyclohexene a t 180' in sol- cyclohexene (111) and 3,4-bis-(hydroxymethyl)-cyclohexene(IT). vent acetic acid-acetic anhydride gave the crude Evidence for I1 was the isolation of its bisphenylurethan derivative.
I 1
v
11T12
T h e possible presence of I11 and/or I V was suggested by the ubservation t h a t the mixture absorbed 755% of one equivalent of h y d r o m ~ i upon catalytic reduction. program in organic chemistry a t Cornell University sponsored by t h e (8) A, S. Dreiding and J. A. H a r t m a n , TIIIS JOURNII., 75, rI.39 B. F.Goodrich Co. ( 2 ) For a closely related preceding paper see A. T. Blomquist, (lO53). M.Passer, C. S. Schollenberger and Joseph Wolinsky, THISJOERKAI., (9) H . Fieselman, Re,., 75, 881 (1942). 79, 4972 (1957). (10) E. G. E. Hawkins, D. J . G. Long and I;. I\'. Major, J . Chcni. S o r . , 1162 (1055). ( 3 ) Abstracted from part of t h e dissertations presented by J. Verdol (11) M . Mousseron, J. Julien and F. Winternitz, Birll. S O c . c h ~ m in February, 1955, and J. Wolinsky in June, 1956, t o t h e Graduate France, [ 5 ] 15, 883 (1948); 1 4 , 80 (1947). School of Cornell University in partial fulfillment of t h e requirements for t h e Degree Doctor of Philosophy. P a r t of t h e work reported here (12) M . Mousseron and R. Jacquier, ibid., [a] 18, 100 (1921), W R S dune by hliss Claire Adami in conjunction with the Honors Pro1 9 , 467 ( 1 0 3 2 ) ; 2 0 , 034 (1953). (13) A Guillemonat, A n s . chim. ( P a 8 . i ~ )[. I l l 11, 170 (1939). gram in Chemistry. (14) 11. Xousseron, R . Jacquier, A. Fontaine and R. Zagcloun. (4) J. P. Bain, THIS J O U R N A L , 68, 038 (1046). Bull. soc. chiin. F r a ~ z c e ,[6] 2 1 , 124F (19.54). ( 5 ) R. Pummerer, F. Aldebert, F. Buttner, F. Graser, 13. Pierson. H . Rick a n d H. Sperber, A?z?z., 583, 101 (1953). (15) 1%.Pommereau, Coinpt. r e n d . , 174, 685 (1022). ( I C ) "Catalogue of Selected Infrared Absorption Spectrograms." (0) pi. 0. Brace reported t h a t cyclohexene and =-pinene d o react with paraformaldehyde a t 200-225' but gave no information about American Petroleum Institute Research, Project 44, National Bureau nf Standards, Washington, D. C. yield o r structure of t h e products (THISJOURNAL, 1 7 , 4SGS (1055)).
(1) T h e work reported here was done a s p a r t of a general research
THERMAL CONDENSATION OF CYCLICOLEFINSWITH FORMALDEHYDE 4977
Sept. 20, 1957
This result is to be expected in view of the enhanced reactivity of an acyclic double bond in this reaction. Hydrogenation data indicated that a t least 90% of the mixture from d-limonene and formaldehyde contained a ring double bond, thus limiting the amount of I X to
