130 MASS. EXPERIMENT STATION BULLETIN 166. 



Glycerides of Monohydkoxy and Dihydroxy Acids. 

 Acetylation. 

 (R . OH . COO)3C3Hs+3 (CHsCOoO = (R . OCH3CO . COOeCsHs+S CH3COOH 

 triglyceride of acetic acetylated glyceride acetic acid 



monohydroxy acid anhydride 



Example: Ricinolcin (C17H32 . OH . COO)3CbHs, 



Saponification. 

 (R . OCHsCO . COO) 3C3H5 +6 KOH 

 acetylated glyceride alkali 



= 3 R . OH . COOK +3 CH3COOK +C3H6(0H) , 

 potassium salt potassium glycerol 



of hydroxy acid acetate 



[R(OH)2COO]3C3Ha + (CH3CO)20 = [R(OCH3CO)2COO]3C3H5+H20 

 triglyceride of acetylated glyceride 



dihydroxy acid 



Example: Dihydroxystearin [Ci7H33(OH)2COO]3C3H6 

 [R(OCH3CO)2COO]3C3H5+9 KOH =3 R(OH)2COOK+6 CH3COOK+C3H6(OH)> 



MONOGLYCERIDES AND DiGLYCERIDES. 



(RCOO)C3H6(OH)2 + (CH3CO)20 =(RCOO) (CH3COO)2C3Hs+H20 

 monoglyceride diaceto-glyceride 



(RCOO) (CH3COO)2C3H5+3 K0H=RC00K+2 CH3C00K+C3H6(0H)3 



(RCOO)2C3H5(OH) +(CH3C0)=0 =(RCOO)!(CH3COO)C3H5+CH,COOH 

 diglyceride monaceto-glyceride 



(RCOO)2(CH3COO)C3H6+3 KOH =2 RCOOK+CHsCOOK+CsHsCOH), 



Free Alcohols. 

 ROH + (CH3CO)20 =CH3COOR+CH3COOH 

 monobasic acetate 



alcohol of alcohol 



CH3COOR+KOH =R0H+CH3C00K 



Examples: Sitosterol, cholesterol, C27H450H 



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- 

 poimds 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 



