98 



of ketone and hydrole will jield on reduction in a (OH-containing) 

 neutral medium a slight amount of pinacone. 



In order to verify this experimentally we have commenced by 

 reducing a sei'ies of ketones by means of aluminium amalgam in 

 80% alcohol. 



The subjoined table gives a survey of the results concerned : 



Disregarding a few irregularities, the following is now apparent 

 from this table : 



1. The methoxy- and methyl group a]3pear to promote in a 

 slight degree the formation of pinacone. 



2. Halogen in the nucleus favours in a high degree the formation 

 of. the hydrole so that, [>articularly with plural substitution, the for- 

 mation of pinacone is nearly, or entirely, prevented. 



3. The position of the substituent in the nucleus does not appear 

 to be of considerable intlnence on the proportion in which hydrole 

 and piiuicone are generated; on the other hand the nature of the group 

 entered seems to be of more importance. 



Hence, many important differences may be obser\'ed in the relation 



1) These hydroles have low melting points; as only small quantities were at our 

 disposal we did not succeed obtaining them in a perfectly pure condition. 



