168 



III. CHEMISTRY OF NEUTRAL FATS 



acetone is then removed by cold acid hydrolysis to give the a-monoglyc- 

 eride, as illustrated below. Daubert and King^ state in their recent re- 



HCOH -HC-C^ ^CH,- 



HoC 0\ ^CH^ 



I X 



HzCOH 



Glycerol 



H2COH 



1,2-Isopropyl- 

 idenegl.\'cerol 



HzCOOCR 



1 ,2-Isopropylidene- 

 3-ac.\lglycerol 



HjCOH 



OCid hydrolysis I 



rzr. ►HCOH 



H2COOCR 



a-Monoglyceride 



view that a large number of investigators have used the Fischer synthesis 

 successfully . 



Daubert and King'' employed 1,2-benzylideneglycerol in place of 1,2- 

 isopropylideneglycerol for preparing pure a-monoglycerides. The reac- 



H2C0C(C6H5)3 



H COClCeHslj 

 HeCOH 

 1 ,2-Benzylideneglycerol 



tions are analogous to those with 1,2-isopropylidenegIycerol. The start- 

 ing product, 1,2-benzylideneglycerol, is the predominant product when 

 trityl acts upon glycerol. 



a-Monoglycerides are likewise formed when 1,3-triphenylmethyl- 

 (trityl) -glycerol is acylated with an aliphatic group and the product is 

 subjected to hydrolysis.'^ Because of the greater stability of the a-carbon 

 over the /3-carbon, an aliphatic acyl group migrates from the /3- to the a- 

 position during hydrolysis. Verkade and co-workers^ have confirmed the 

 earlier investigation of Jackson and King.^ 



HsCOH 



H ioH-^^^25H5hci 



HeCOH 

 Glvcerol 



HaCGClCeHsls 



-HCOH — 



HsCOCteeHsls 



1,3-Triphenyl- 



methylglycerol 



H2C0C(CeH5)3 H2COOCR 



HCOOCR c^^c^JoH -HCOH 



H2C0C(C6H5)3 HaCOH 



2-Acyl-l,3-tri- a-Mono- 



phenylmethylglycerol glyceride 



6 B. F. Daubert and C. G. King, Chem. Revs., 29, 269-285 (1941). 



« B. F. Daubert and C. G. King, ./. Am. Chem. Soc, 60, 3003-3005 (1938). 



7 D. T. Jackson and C. G. King, /. Am. Chem. Soc, 55, 678-680 (1933). 



* P. E. Verkade, J. van der Lee, and W. Meerburg, Rec. trav. chim., 54, 716-724 

 (1935). 



