The structures of 1-deoxy-(N-methyloctanamido)-D-glucitol (MEGA-8) and 1-deoxy-(N-methylundecanamido)-D-glucitol (MEGA-11)

1-Deoxy-(N-methyloctanamido)-D-glucitol, C15H31NO6 (MEGA-8), crystallizes in space group P2(1)2(1)2(1), Mr = 321.4, a = 4.865 (1), b = 9.186 (3), c = 39.097 (9) A, V = 1747.24 A3, Z = 4, Dx = 1.22 Mg m-3, lambda (Cu K alpha) = 1.5418 A, mu = 0.78 mm-1, F(000) = 704, R = 0.035 for 1318 reflections. 1-Deoxy-(N-methylundecanamido)-D-glucitol, C18H37-NO6 (MEGA-11), crystallizes in space group P1, Mr = 363.5, a = 4.950 (1), b = 5.6027 (8), c = 19.162 (4) A, alpha = 83.19 (2), beta = 89.76 (2), gamma = 76.28 (2) degrees, V = 512.64 A3, Z = 1, Dx = 1.18 Mg m-3, lambda (Mo K alpha) = 0.7107 A, mu = 0.093 mm-1, F(000) = 200, R = 0.061 for 1898 reflections. The glucitol C-atom-chain conformation is different in the two structures. In MEGA-8 it is fully extended, whereas in MEGA-11 it is bent. The alkyl C-atom chains are fully extended in both structures. The molecular packing is different. In MEGA-8 it is head-to-head bilayer with intercalating alkyl chains, whereas in MEGA-11 it is monolayer head-to-tail with non-intercalating alkyl chains. The hydrogen bonding in MEGA-8 is a finite chain; in MEGA-11 it includes a homodromic four-bond cycle.