Abstract1,3,5‐Trideoxy‐1,3,5‐tris(dimethylamino)‐cis‐inositol (TDCI) and 1,3,5‐trideoxy‐1,3,5‐tris(trimethylammonio)‐cis‐inositol (TTCI) were prepared by methylation of 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol (TACI). The ability of TDCI to form both intermolecular and intramolecular H‐bonds, as demonstrated by X‐ray diffraction, is probably responsible for the good solubility of TDCI in almost every common solvent. TTCI was found to be a polyol of unusual high acidity (pK1= 8.14 ± 0.02, pK2= 13.0 ± 0.2). This phenomenon could be explained by electrostatic interactions between the charged subs