( ^74 ) 



'J. SpJiiiiiig' off of' H.,(), ill such ;i niaiuier that the group OH 

 departs with the H of a ('-atom, for example: 



V' C— CH, -^ >C C— ( 



OH/ \^,jj CH/\/ 



CH, 



Nkf's view of hen/pinacoiu' is in accordaiu'C Avith this. 



The object of this representation is to abandon the idea of an 

 intramolecular atomic rearrangement and to substitute so-called nor- 

 mally-proceeding reactions. 



2. Splitting oil' of H.^O in such a manner that the group OH 

 departs with an 11 of the second Oil grou]), for e\ami»Ie: 



CH3. V\\, CH3. .CH. 



>COH— COH< -» >C^ C< ') 



CH/ \CH, CH/ \^^y \CH, 



Nkf ^) : "P]s ist Jetzt x'ollkomuHMi klar, dass diese Reaction (Umwand- 

 lung der 1.2 Glycolen in Ketonen) bei welcher eine scheiidmre 

 Yerschiebung der Hydroxyle eintritt, auf eine inlcMinediaire Bildiing 

 von Alkvlenowd ziirrickzufTihren ist." 



/' /H 



C,H,-C-OH C,H,-C. 



C,H,— C— OH \ii 



Tn this re|)resenlation ^ve still a(bnit an inlramolecular atomic 

 rearrangement; not, however, with the 1.2 glycols l)ut with the oxides. 



In the transfoi-mation of hydr( (benzoin ijito dijihenylacetaldehyde, 

 and now again in that of benz|)inacone into benzpinacoline, 1 have 

 shown that the lirst tlieory is untenable. In view of this I consider the 

 existence of a trimethylene-ring also in the transformation of i)inacone 

 into })inacoline too as being less probable. Of course a direct proof, 

 as in the case of the aromatic r^-glycols, cannot be produced, but, 

 pi-ovisionall} , this theory seems to me to lack all fonndation. It 

 looks to me as if Nkf himself is abandoning this theory, because, 

 whilst formerly ') he considered the trimethylene-ring as very ]n'0- 



^) Couturier. Awn. chini. phys. [0] '26 p. 434. Erlenmeyer. Ber. 14 p. 322. Note. 

 Zelinsky and Zeukow. Bcr. 34 p. 3251. 

 ') Erlenmeyer. Ann. 310 p. 84. 



3) Ann. 335 p. 243. 



4) Ann. 318 p. 38, 



