Hydroxy acids Alpha, Anhydrides

In this case we have formed an inner anhydride which will be explained presently, when we consider the hydroxy acids. These differences in the reaction of alpha-y beta- and gamma-hdXogtn acids are characteristic of alpha-y beta-.y and ga/w/wo-substituted acids in general and will be more clearly shown when we consider them in connection with the hydroxy acids (p. 241). 

Both reactions (3) and (4) take place also between two molecules of the alpha- hydroxy acid itself in which case the product is termed an anhydride as discussed below in (7). 

Anhydrides.—(7) The most striking reactions of the hydroxy acids are those in which the alpha- beta- and gamma-hydioxy acids react differently. These reactions involve the loss of water and the formation of anhydrides. The reaction takes place simply under the influence of heat, and shows the different effect which is produced by a difference in the position of the hydroxyl group in relation to the carboxyl. 

Upha- Ry roxy Acid Anhydrides.—When an alpha-hydroxy acid is heated, or when it simply stands over sulphuric acid, two molecules react together as an alcohol-acid compound, in the manner described above in (3) and (4). The alcoholic hydroxyl of one molecule reacts with the acid hydroxyl of the other molecule and water is lost with the formation of a single anhydride which is really an ester. This compound then loses a second molecule of water by the reaction between the remaining alcoholic and acid hydroxyl groups forming a double anhydride or a double ester as discussed above in (6). The name of such double anhydride takes the termination ide in place of ic of the original 16... 

This formation of single and double anhydrides from two molecules of an amino acid by loss of first one and then a second molecule of water is exactly analogous to the similar formation of anhydrides in the case of hydroxy acetic acid and all alpha hydroxy acids (p. 241). 

UVA 2-hydroxy-4-octyloxybenzophenone 2-hydroxy-4-methoxybenzophenone 2-(2H-benzotriazol-2-yl)-p-cresol 2-(2H-benzotriazole-2-yl)-4,6-di-tert-pentylphenol 2-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetraethylbutyl)phenol 2,4-di-tert-butyl-6-(5-chloro-2H-benzotriazole-2-yl)-phenol 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy) phenol ethyl-2-cyano-3,3-diphenylacrylate HAS 1,3,5-tri-azine-2,4,6-triamine, N,N [1,2-ethane-diyl-bis[[[4,6-bis[butyl-(1,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl] imino]-3,1 -propanediyi] bis[N ,N -dibutyl-N ,N -bis(1,2,2,6,6-pentamethyl-4-piperidinyl)- bis(2,2,6,6-tetramethyl-4-piper-idyl) sebacate 2,2,6,6-tetramethyl-4-piperidinyl stearate N,N -bisformyl-N,N -bis-(2,2,6,6-tetramethyl-4-piperidinyl)-hexamethylendiamine alkenes, C20-24-.alpha.-, polymers with maleic anhydride, reaction products with 2,2,6,6-tet-ramethyl-4-piperidinamine 1,6-hexanediamine, N, N -bis(2,2,6,6-tetramethyl-4-piperidinyl)-, polymers with 2,4-di-ohloro-6-(4-morpholinyl)-1,3,5-triazine 1,6-hexanediamine, N,N -bis(2,2,6,6-tetramethyl-4-piperidinyl)-, polymers with morpholine-2,4,6-trichloro-1,3,5-triazine reaction products, methylated Phenolic antioxidants ethylene-bis(oxyethylene)-bis(3-(5-tert-butyl-4-hydroxy-m-tolyl)-propionate) 2,6,-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5,-triazine-2-ylamino) phenol pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate) 2-(1,1 -dimethylethyl)-6-[[3-(1,1 -dimethylethyl)-2-hydroxy-5-methylphenyl] methyl-4-methylphenyl acrylate isotridecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate 2,2 -ethylidenebis (4,6-di-tert-butylphenol) 2,2 -methylenebis(4-ethyl-6-tertbutylphenol) 3,5-bis(1,1-dimethyethyl)-4-hydroxy-benzenepropanoic acid, C13-15 alkyl esters phenol, 4-methyl-, reaction products with dicyclopen-tadiene and isobutene Phosphite trinonylphenol phosphite isodecyl diphenyl phosphite... 

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