422 



SO that the arrangement of the molecule for the diterpene may be stated as 

 follows ■ — 



CH 



H.C 



HC 



CH 



CH, 



The other possible arrangement with two molecules of pinene would be 

 expected to yield an inactive compound. In this arrangement one of the pinene 

 molecules has been rotated in the plane of the paper. The reactions of this diter- 

 pene are in many respects similar to those of diphem^l, which substance it some- 

 what resembles in appearance, and this similarit}/ might perhaps suggest a 

 corresponding linkage, but the results did not indicate a molecule with 

 34 h\-drogen atoms, and from three analyses the following percentages of 

 hydrogen were obtaint-d: 11-75, ii-74, and 11-74, and over 88 per cent, of carbon 

 with each. 



A. Etard and (i. Meker, ("Compt. rend." 1898, 126, 526-529) prepared 

 a crystalline dicamphene hydride by treating pinene hydrochloride with sodium. 

 This substance melted at 75°, boiled at 326-327°, and had specific rotatory power 

 [«]„=-H5°27'. 



E. A. Letts, ("Ber." 13, 793-796J by treating i)inene hydrochloride with 

 sodium, had previously obtained, in addition to other bodies, a crystalline sub- 

 stance which melted at 94°, and to wliirli tlie formula C.^,, H;;., was given. 



The close agre< imut bclwccn tlie specific rotation of Etard and Maher's 

 substance, and that of Phyllocladene, might suggest a similarity, but there is a 

 difference of 20° in their melting points. The melting point of Letts' substance 

 is, however, in closer agreement. 



The results of the analyses of Phyllocladene sliow Uic molecule to have 

 32 hydrogen atoms, so that the iiiole( uh caiuKjt be coiislructed with only a 

 single linkage. 



