2,2-Dimethyl-5-nitroso-1,3-dioxan-5-yl benzoate, 2,2-dimethyl-5-nitroso-1,3-dioxan-5-yl 4-chloro­benzoate and 5-nitroso-1,3-dioxan-5-yl 4-chloro­benzoate

The crystal structures of 2,2-dimethyl-5-nitroso-1,3-dioxan-5-­yl benzoate, C₁₃H₁₅NO₅, (I), 2,2-dimethyl-5-nitroso-1,3-dioxan-5-yl 4-chloro­benzoate, C₁₃H₁₄ClNO₅, (II), and 5-nitroso-1,3-dioxan-5-yl 4-chloro­benzoate, C₁₁H₁₁NO₅, (III), have been determined in order to gain insight into the conformational preference of α-benzoyl­oxy­nitroso. Unfavourable 1,3-diaxial inter­actions force (I) and (II) to crystallize in the 2,5 twist-boat conformation, whereas compound (III), lacking this destabilizing inter­action, crystallizes in the chair conformation.