74 



MASS. EXPERIMENT STATION BULLETIN 151. 



Examples: 



Free Alcohols. 



ROH + (CH.,CO)20 = CHaCOOR+CH3COOH 

 monobasic acetate 



alcohol of alcohol 



CH3COOR +KOH = ROH +CH3COOK 

 Cholesterol, phytosterol, C2-H430H 



Considerable variation is possible in writing the above formulas which, 

 at best, poorly express the structure. In some instances the reaction is 

 indicated at some sacrifice of form. 



Calculated Data from the Acetyl Number. 

 The acetyl number (c) serves to measure the amount of hydroxy com- 

 pounds in an oil, fat or wax; and in case only one such compound of 

 known molecular weight (m) and number of hydroxyls (d) is present, 

 its amount (H) can be readily calculated by the following formula: — 



H = 



56108 d 



The derivation of the formula is comparativeh^ simple. The theoreti- 

 cal acetyl number of a compound containing (d) hydroxyl groups is — 



56108 d 

 ni 



The amount of such a compound in an oil, fat or wax is, therefore — 



c _ cm 

 56108 d 56108 d 



The same results may be calculated more easily from the following table, 

 dividing the determined acetyl number by the theoretical acetyl number, 

 or multiplying by its reciprocal : — • 



Acetyl Number on Original Product {Massachusetts Method). 



Glycerides. 



