SYNTHETICAL EESEAECHES ON ETHERS. 



67 



Name. 



Isomeric 



Butyrone . . . . 

 Dietliylated acetone 



Formula. 



;cEtHa 



".CPrO J 



rCEtgHI 

 IcMeOj 



Boiling-point. 



144° C. 

 138° C. 



The carboketonic ethers show in a very remarkable manner the boiling-point values 

 of different atoms of hydi-ogen, whilst the two isomeric bodies of this series also exem- 

 plify what has just been stated regarding the inference of constitution from the boiling- 

 point. Reduced to the radical type, these bodies may be thus tabulated : — 



Name. 

 Ethylic acetone carbonate . . 



Ethylic methacetone carbonate 



Ethylic dimethacetone carbonate 



Ethylic ethacetone carbonate . 



Ethylic diethacetone carbonate 



already one atom of methylic hydrogen rep 



fC(CMeO)H2 ) 

 (COEto* I 



(C(CMeO)MeH) 

 (C O Eto / 



(C(CMeO)Me_, ) 

 (COEto ) 



fC(CMeO)EtH | 

 IcOEto I 



(C(CMeO)Et2 I 

 Ic O Eto / 



Boiling-point. 



176° C. 

 184° C. 

 184° C. 

 195° C. 

 211° C. 



It will be seen from these formulae that the lowest of the carboketonic ethers has 



aced by the radical acetyl (C Me O), conse- 



quently the further substitution of methyl and ethyl takes effect upon the second and 

 third atoms of methylic hydrogen. When in the formation of ethylic methacetone 

 carbonate the second atom of hydrogen becomes replaced by methyl, the boiling-point 

 rises only 8° C. ; but when the third atom of hydrogen is in like manner exchanged for 

 methyl the boiling-point is not appreciably affected, ethylic methacetone carbonate and 

 ethylic dimethacetone carbonate both boilmg at the same temperature. 



The introduction of ethyl in the place of the second atom of hydrogen, in passing 

 from ethylic acetone carbonate to ethylic ethacetone carbonate, raises the boiling-point 

 19° C, or 9°"5 for each addition of CHg. Ethacetone carbonate contains CHjmore 

 than methacetone carbonate, and the addition is also here made to the group occupying 

 the place of the second atom of hydrogen : in this case the addition of C Hj is also 

 attended by a rise of only 11° in the point of ebullition. Finally, the conversion of 

 ethylic ethacetone carbonate into ethylic diethacetone carbonate, unlike the corre- 

 sponding change in the methyl compounds, is attended with a marked though small rise 

 of boiling-point equivalent to 8° C. for each C Hg added. 



* Eto = Ethoxyl = (C, H, 0). 



