J. Org. Chem., Vol. 36, No. 9,1970
CYCLOHEXANONE PEROXIDES
Macrocyclic Synthesis. 11.
3059
Cyclohexanone Peroxides
BUSCH PAUL R. STORY,BUNGELEE, CLYDEE. BISHOP,DONALD D. DENSON, AND PETER Department of Chemistry, The University of Georgia, Athens, Georgia 30601 Received March 86, 1969 The reaction of cyclohexanone with hydrogen peroxide to yield both the dimeric and trimeric cyclic peroxides has been investigated. It has been found that tricyclohexylidene peroxide is the kinetic product under most conditions and that dicyclohexylidene peroxide is easily formed from it. Improved syntheses of the peroxides, particularly for the trimer, have resulted.
The thermal and photochemical decomposition of peroxides of cyclic ketones has been found to provide a general and facile synthesis of macrocyclic compounds. For this reason a better understanding of the synthesis of the requisite peroxides is required. The most important such peroxides are those of cyclohexanone. The term “cyclohexanone peroxide” has been applied to a number of different compounds, usually in the generic sense to mixtures of peroxides which find application as initiators in polymerization. Frequently, the actual structure of the peroxide in hand is not known. I n general, yields are low and there is insufficient information about the intermediates and complex equilibria involved in the synthesis of cyclohexanone peroxides. This report is concerned primarily with just two of the several cyclohexanone peroxides, dicyclohexylidene peroxide (2) and tricyclohexylidene peroxide (1). We have correlated much of the available data on the cyclohexanone-(hydrogen peroxide) reaction with our own findings to develop a mechanistic scheme which, in turn, has led to improved synthesis of these peroxides (1, 2).
dihydroxydicyclohexyl peroxide (4) , even in the presence of a large excess of hydrogen peroxide (eq 1).
8
+
HOO OH HOOH
6
=== J
4
The presumed intermediate, 3, could not be isolated in this case; however, it should be noted that the corresponding derivative of a-halocyclohexanones is kno~n.~~~ I n acidic solutions, depending on acid concentration, more highly peroxygenated compounds (5 and 6) are formed. As pointed out by Antonovskii, et aL12earlier investigators had assumed, and quite reasonably, that the mo:re highly peroxygenated derivatives, 5 and 6, were derived from 4 (eq 2).8-59798Antonovskii, et a1.,2
5
v 1
2
Probably the focal point of present knowledge is the paper by Antonovskii, Kesterov, and Lyashenko2 who have made a detailed study of the acid-catalyzed reaction of cyclohexanone and hydrogen peroxide. These investigators have, in part, rewritten the sequence of intermediates proposed by Criegeela by Kharasch and S o s n o v ~ k yand , ~ by other^.^ It was confirmed12as asserted by Kharasch and Sosnovsky14that treatment of cyclohexanone with hydrogen peroxide in neutral solution yields only the 1,l’(1) P. R. Story, D. D. Denson, C. E. Bishop, B. C. Clark, Jr., and J.-C. Farine, J . Amer. Chem. Soc., 90, 817 (1968). (2) V. L. Antonovskii, A. F. Nesterov, and 0. K. Lyashenko, Zh. Prikl. Khim., 40, 2555 (1967);J . A p p l . Chem. U S S R , 40, 2443 (1967) (Consultant’s Bureau English translation). (3) R. Criegee, W. Sohnorrenberg. and J. Reoke, Juslus Liebigs A n n . Chem., 666, 7 (1949); R . Criegee and G. Lohaus, ibid., 688, 6 (1953). (4) M. S. Kharaech and G. Sosnovsky, J . Org. Chem., 28, 1322 (1958). (5) (a) N.Brown, M. J. Hartig, M. J. Roedel, A. W. Anderson, and C . E. Sohweitzer, J. Amer. Chem. Soc., 77, 1756 (1955); (b) W. Cooper and W. H. T. Davison, J . Cham. Soc., 1180 (1952); ((1) N. A. Milae, 8. A. Harris, and P. S. Panagiotakos, J . Amer. Chem. Soc., 6 1 , 2430 (1939).
report evidence to the contrary. These investigators conclude that 1-hydroxy-1’-hydroperoxydicyclohexyl peroxide (5) appears to form directly from 3 in “weakly” acidic solutions, Le., eq 3. This conclusion is based on 3 +
Q:;
.---.L
5
+
H,O+
(3)
3-H+
their observation that conversion of 4 to 5 is appreciably slower than formation of 5 from cyclohexanone and hydrogen peroxide with acid (eq 3). Their argument is difficult to evaluate, however, because of the lack of data reported in the papere2 (6) M. Sohulz, K. Kirschke, and E. Hohne, Chem. Ber., 100, 2242 (1967). (7) A. Rieche, Angew. Chen., 7 8 , 57 (1961). (8) M.Schulz and K. Kirachke, Advan. Heterocycl. Chen., 8, 165 (1967).
3060 J . Org. Chem., Vol. 35, No. 9, 1970
STORY, LEE, BISHOP,DENSON, AND BUSCH
In more concentrated acid, 3 is converted to the gem-dihydroperoxide (7) and the 1 , l '-dihydroperoxydicyclohexyl peroxide ( 6 ) is formed by reaction of 3-H+ and 7, according to Antonovskii, et aL2 (eq 4).
3-H+
o
