Solid phase conformational analysis of a 13-membered heterocycle: 8,13-Dioxo-1,4,7-trioxacyclotridecane (diethylene glycol cyclic adipate)

The crystal structure of the title compound (C10H16O5) has been determined by X-ray diffraction methods in order to ascertain the preferred conformation. Crystals are monoclinic, space group P21/c (No. 14) with a = 8.020(2), b = 16.188(1), c = 8.559(1) Å, β = 99.87(1), V = 1094.7(3) Å Z = 4, D = 1.312 g · cm, λ(MoKα) = 0.71069 Å, μ = 0.9 cm−1, F(000) = 432, T= 293 K. The final R was 0.045 for 1026 observed reflections. The conformation is of the [13333] type with corners at C2, C3, C6, C9 and C12. Both ester groups are in syn conformation.