Crystal structures of (±)-1,2:4,5-di-O-isopropylidene-myoinositol and (±)-1,2:5,6-di-O-isopropylidene-myo-inositol: a conformational analysis

(±)-1,2:4,5-Di-O-isopropylidene-myo-inositol (1), C₁₂H₂₀O₆, crystallises in the monoclinic space group, C2/c with unit-cell dimensions a = 22.587(3), b = 5.4204(3), and c = 22.174(4) Å. (±)-1,2:5,6-di-O-isopropylidene-myo-inositol (2), C₁₂H₂₀O₆, crystallises in the monoclinic space group, P2₁/n with a = 11.543(3), b = 6.860(1), and c = 16.895(4) Å. The inositol ring of 1 and 2 has a chair and skew conformation, respectively. Based on the crystalline conformations of 1 and 2, steric and hydrogen bonding features of the hydroxyl groups are discussed.