The nuclear synthesis of olefins through the ß-bromo ethers has been used in a systematic survey of the hexenes. Ten of the thirteen structurally possible members of this family have been prepared, including those previously unknown. The method is shown to be applicable to the synthesis of monoalkyl, symmetrical and unsymmetrical dialkyl ethylenes. It is believed the method will ultimately prove applicable also to the trialkyl and tetraalkyl ethylenes.The confusion which has existed in the physical constants of the olefins is beginning to disappear. A definite relation is shown to exist between the physical properties and molecular structure of the hexenes. Certain rules have been formulated relating the boiling points, densities and refractive indices of the hexenes to their structure.Eight bromohexyl ethyl ethers, three hexenes and five dibromohexanes are herein described for the first time.

Ethylene succinate as a typical example of a condensation polymer1 has been submitted to further study with the view of gaining more information in regard to its structure. The presence of the structural unit,1 I, in this ester has been established by the methods used in its synthesis,2,3 by its chemical behavior, and by its analytical composition.2,3Of the various polymeric forms described in this paper, the apparent molecular weights indicate average values of 6 and 23, respectively, for the number of structural units contained in each molecule of the lowest and highest polymers. It is assumed that these units are joined together in a linear fashion by real primary valences, as in II. Since it is very improbable that there are free valences at the ends of the resulting chains, the problem of the structure of these polymers resolves itself into finding whether the end valences are mutually saturated with the formation of very large rings or are saturated by univalent groups of some kind. -0-(CH2)2-0-0C-(CH2)2-C0-0-(CH2)2-0-0C-(CH2)2-C0-0-(CH2)2-O-OC-(CH2)2-CO-, etc.(II) Any of the reactions by which this ester is prepared offers the formal possibility of establishing either rings (closed chains) of 8, 16, 24, Neutral Ethylene Succinate.-This ester is prepared by heating suc-

mann).-Phenylfluorenol methyl ether was prepared according to the directions of Schlenk and Bergmann.6 However, while they report fluorescence of the solution of the methyl ether, no trace of such fluorescence was shown by our solutions.Five grams of sodium powder was allowed to react with 10 g. of 9-phenylfluorenol methyl ether in 150 cc. of absolute ether in a sealed flask. In less than half an hour the solution was red in color. When the reaction was complete the mixture was treated with benzyl chloride (3 cc.) until no more red sodium derivative remained. The mixture was hydrolyzed, the ether solution was well washed with water and the solvent was then removed under reduced pressure. The crystalline residue was digested with cold methyl alcohol and filtered; weight 11.10 g.; m. p. 136-136.5°. From the alcoholic filtrate an additional 0.32 g. was isolated, making the total yield equivalent to 99%. After being recrystallized from »-propyl alcohol, acetic acid or ligroin, the crystals melted at 138-138.5°( corr. 140.3-140.8°). When mixed with 9-benzyl-9-phenylfiuorene made by the other methods the melting point remained the same.In another experiment the mixture of the reactants was kept cold, and after hydrolysis the reaction product was obtained by allowing the ether to evaporate at room temperature. Only the compound melting at 138-138.5 °was obtained. Summary 9-Benzyl-9-phenylfluorene as prepared from phenylbiphenylenemethylmagnesium bromide and benzyl chloride is identical with the product formed by interaction of 9-bromo-9-phenylfluorene and benzylmagnesium chloride. Furthermore, the same compound was obtained in 99% yield from the action of benzyl chloride on 9-sodium-9-phenylfluorene, and no low-melting isomer was produced in this reaction.Ann Arbor, Michigan [Contribution No. 35 from the Experimental Station of E. I. du Pont de Nemours and Company] STUDIES ON POLYMERIZATION AND RING FORMATION. V. GLYCOL ESTERS OF OXALIC ACID