This dissertation has been microfilmed exactly as received 69-4845 BEGLAND, Robert Walter, 1941- PARTICIPATION AND STERIC EFFECTS OF NEIGHBORING DIVALENT OXYGEN. The Ohio State University, Ph.D., 1968 Chemistry, organic University Microfilms, Inc., Ann Arbor, Michigan PARTICIPATION AND STEPJ.C EFFECTS OF NEIGHBORING DIVALENT OXYGEN DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Robert Walter Beglnnd, B.S., M.S. * it * * it it * The Ohio State University 1968 Approved by Adviser \J Departmeirt of Chemistry DEDICATION This dissertation is dedicated to my w ife June, ny con Michael Brian and my son Douglas Samuel. i i ACKNOWLEDGMENT The author wishes to express his appreciation to Dr. L. A. Paquette for his guidance, encouragement and considerable time spent in the course of this research. The author also wishes to express his appreciation to his parents, Mr. and Mrs. Walter C. Bcgland, for their assistance and encouragement throughout his college training, and to lir. and Mrs. Lester Berndt. i i i VITA July 23, 1941 Born - Oak Park, Illinois 1963 B.S. in Education, The Ohio State University Columbus, Ohio 1965 M.S., The Ohio State University Columbus, Ohio 1968 Ph.D., The Ohio State University Columbus, Ohio PUBLICATIONS 1. Transannular Participation of Ether Oxygen in the Hydrolysis of a Mesocyclic Dienamine, J. Am. Chen. Soc. 87, 3784 (1965). 2. Stabilized Derivatives of cis,cis,cis-1,3.5-Cyclodecatricne Keto-Enol Tautomerism in 2,3-DicarboiEeth.oxy-cis,c is -3,5~ cyclodecadienones and c.is-3-Cycloalkenones. J. Am. Chem. Soc. 88, 4685 (1966). 3. Oxocane. Synthesis and Conformational Isomerization. J. Org. Chem. 32, 2723 (1967). 4. The Interception of Homoallylic Cations by Neighboring Hydroxyl. J. An. Chem. Soc. 90, (1968). 5. Acid-Promoted Rearrangements Involving Transannular Ether Oxygen Participation. J. Am. Chem. Soc., 90. (1968). FIELDS OF STUDY Major Field: Organic Chemistry iv TABLE OF CONTENTS Page D e d i c a t i o n ....................................................................................................... 11 Acknowledgment .............................................................................................. I l l Vita . ............................................................................................................ iv List of Tables .............................................................................................. vi List of Illustrations ..................................................................... v ii Introduction .................................................................................................. 1 Part I: Acid-Promoted Rearrangements Involving Transannular Ether Oxygen Participation . 4 Part II: Oxocane: Synthesis and Conformational Isomerization ........................... 15 Part III: Acetolycis of Oxocan-3-yl £ 1^1 3 ,4 , 7 , 8 - Tetrahydro“2H-oxocin-3-yl Brosylates ................... 18 Part IV: The Interception of Homoallylic Cations by Neighboring Hydroxyl ............................................... 42 Part V: Stabilized Derivatives of cls.cis.cis-1,3,5- Cyclodecatriene. Keto-Enol Tautomerism in 2.3-Dicarbomethoxy-cis,cis-3,5-Cyclodecadienones and cis-3-Cycloalkenones ............................................... 57 Part VI: Novel Products from the Reaction of 1-Diraet.hylamino-l,3-Cyclooctadiene with Methanesulfonyl Chloride ............................................... 84 Experimental .............................................. 95 R eferences .............................................. 144 v LIST OF TABLES T able Page 1. Acetolysis Rate Data for 27. and 4 3 ........................ 24 2. Relative Capabilities of Several Heteroatomic Groups for Anchimeric Assistance ...................................... 56 3. Ultraviolet Absorption Data for Soiae Cyclic Polyolefins ......................................................................................... 66 4. Infrared Absorptions of Some 2,3-Dicarboraethoxy- cis, cis-3,5-cyclodecadicnones and cis-3" cyclonlkenones ................................................................................ 71 5. Ultraviolet Absorption Data of Some 2,3- Dicarboraethoxy-cis,cis-3,5-cyclodecadienones and cis-3-cycloalkenoncs ............................................... 74 6. Chemical Shift Values (6 units) and Enol Contents of Some 2,3-Dicarborr.ethoxy-cis, cis- 3,5-cyclodecadienones and cis-3-cycloalkcnones . 76 7. Sulfones Formed Under Various Reaction C onditions ......................................................................................... 86 8„ Example of a Solvolytic Rate Calculation ..................... 120 9. Solvolytic R.r.te Data Experimentally Determined for 27 and 4S ••••••••••»••••«••• 121 v i LIST OF ILLUSTRATIONS Figure Page 1. Partial NMR Spectra of 2,3-Dicerbonethoxy- 3- c is -cy c1ono neno ne ( 1 3 3 ) ............................................................... 80 v i i INTRODUCTION Leonard, in his studies of the transannular reactions of medium-sized heterocyclic molecules, was able to detect transa\uiular N-C^q and interactions in the spectra of 1 2 ketones such as 1. and 2 In addition, such ketones could be converted to their respective bicyclic salts upon treatment with strong acids. By contr*ast, l-oxacyclooctan-5-one <3) CH HCIO, -v l OH h c ip. CIO/ © 2 exhibited no such transannular effects in its spectra, a result which was attributed to the relatively low order of electron- donating ability of oxygen.^ 3 Despite the marginal nucleophilicity of ether oxygen, many facts are available to suggest that it should be entirely capable of transannular bonding in carbontum ion reactions. With particular 1 regard to aliphatic and alicyclic ethers, the anomalously rapid rates of acetolysis of 4-methoxybutyl and 5-methoxype-ntyl brosylates have suggested that these reactions proceed through cyclic oxonium ions. The enhanced solvolytic behavior of UJ-(2-tetrahydrofuranyl)-3-propyl brosylate also pointed to anchimeric assistance by ether oxygen and formation of a bicyclic oxoniun ion intermediate/* Additional evidence 5 of such neighboring group participation has recently been reviewed. The work described herein was undertaken to study both the transannular reactions and neighboring group participation of divalent oxygen. Also considered are the steric effects brought about by the replacement of a methylene group by an oxygen atom in medium-sized rings. Because the present investigation has dealt with a number of different problems relating to the effects of divalent oxygen, the various aspects of this work are divided into the following sections: Part I . Acid-promoted rearrangements involving transannular ether oxygen participation are presented. The attempted synthesis of 3,4, 7.8-tetrahydro-211-oxocin and the problems which arose from this work are discussed. Part I I . The low temperature nmr spectra of oxocane are compared to those of cyclooctane in terms of the strain minimization brought about by replacement of a methylene group by an oxygen atom. Part III. The rates and products of acetolysis of oxocan-3-yl and 3.4.7.8-tetrahydro-2H-oxocin-3-yl brosylates are presented. These com­ pounds are compared with their carbocyclic analogs and the dramatic effects of the ether oxygen upon the products obtained are discussed. Part XV. The silver ion-induced cyclization of selected cis- and trnns-iodohydrlns in which the iodine substituent occupies a homo- allylic position has been investigated. Evidence is presented which supports the fact that ring closure proceeds by way of intermediate homoallylic cations which are subject to intramolecular nucleophilic attack by the neighboring hydroxyl group. The ambident electrophilic nature of homoallylic cations is considered. Part V. Stabilized derivatives of cis. cis. c.is-1.3,5-cyclodecatriene were prepared and the keto-enol-fcau-tomerism in the 2,3-dicarbomethoxy- cis, cis-3.5-cyclodccadienones and cis-3-cycloalkcnoncs was studied. ^ne cnol/keto ratio (K£) is considered in terms of probable stereo­ chemical and steric factors. Part VI.o The reaction of l-dimcthylamino-l ,3-cyclooctcdiene with methanesulfonyl chloride gave seven products. The structures of these products and the mechanisms of their formation are discussed. PART I ACIB-PR01DTED REARRANGEMENTS INVOLVING TRANSANNULAR ETHER, OXYGEN PARTICIPATION Introduction The phenomenon of transannular interaction is perhaps the most remarkable of a number of unique features exhibited by medium-sized rings. The origin of this characteristic is found in the existence of certain conformations wherein opposite sides of the ring are brought into close proximity. The pioneering work in this area, due to Prelog^ end Cope^, has centered predominantly upon transannular hydride shifts. These studies have shown that when substantial carboniurn ion character develops in reaction intermediates involving mesocycles, transannular rearrangements are very likely to be of great importance. For example, the action of phosphoric acid on 4. results in the formation of 6-methyl- g cyclodecanone by a 1,6-hydride shift. CH CH. 4 5 A further distinguishing feature of medium-sized rings is their tendency to convert to bicyclic structures to relieve existing non­ bonded interactions. To illustrate, solvolysis of 4-cycloocten-l-yl brosylate (6)in acetic acid yields acetates of 7 and 8 in addition 4 5 to 4-cyclooctenyl-l-acetate \X)B:is ■-H -■OH 6 7 8 1 2 Leonard, * in a broadening