monozaharida : CxH2xOx
CxH(x+1)O[(OH)(x-1)] + (x-1)C4H6O3 ⇒ CxH(x+1)O[(OCO-CH3)(x-1)] + (x-1)CH3COOH
ester: C(3x-2)H(4x-2)O(2x-1) M = 12(3x-2) +4x-2 + 16·(2x -1) = 246
72x - 42 = 246 72x =288 x = 4
raspuns : nr. grupe OH = x-1 = 3
A = O=CH-CH(OH)-CH(OH)-CH2OH