Abstract
The title compounds, 6-(octyloxy)hexa-hydro-furo[3,2-b]furan-3-ol, C14H26O4, 6-(decyl-oxy)hexa-hydro-furo[3,2-b]furan-3-ol, C16H30O4, 6-(do-decyl-oxy)hexa-hydro-furo[3,2-b]furan-3-ol, C18H34O4, and 6-(tetra-decyl-oxy)hexa-hydro-furo[3,2-b]furan-3-ol, C20H38O4, consist of a polar headgroup (isosorbide) and a lipophilic alkyl chain linked via an ether bridge. Isosorbide is a biobased diol, containing two fused furan rings. One inter-molecular hydrogen bond connects the mol-ecules between the free endo hy-droxy group and the opposing ether oxygen of the V-shaped head group. Thus the mol-ecule layers inter-lock like in a herringbone pattern parallel to the bc plane.
Highlights
The Flack parameters and associated e.s.d. values in the title compounds are À0.7 (5) (3a), À0.18 (13) (3b), 1.6 (9) (3c) and À1.1 (10) (3d)
Because each polar headgroup functions as hydrogenbond acceptor and donor, the hydrogen bond reinforces the connection between the layers and strengthens the coherence within the layer, interlocking the molecules into a herringbone pattern parallel to the bc plane
Synthesis and crystallization angle O2—C2Á Á ÁC2—O2i (Table 1) is between 52 and 55. This intermolecular torsion angle directly corresponds to the opening angle of the herringbone pattern (Figs. 3 and 4)
Summary
The Flack parameters and associated e.s.d. values in the title compounds are À0.7 (5) (3a), À0.18 (13) (3b), 1.6 (9) (3c) and À1.1 (10) (3d). None of the esd values meets the criterion for enantiopure-sufficient inversion-distinguishing power (Flack & Bernardinelli, 2000), which is expected given that compounds 3a, 3b and 3d were measured using Mo radiation and Friedif values are in the range of 6 to 7 (Mo) and 33 to 35 (Cu), respectively (Flack et al, 2007; Flack, 2008). The Flack parameter of the reported compounds is essentially inconclusive. The structure analysis confirms the formation of compound 3a– d. The other compounds with chain lengths of C8, C10 and C12 have a strong structural similarity and are not shown explicitly.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have