IUCr journals

The absolute configuration of 1-epialexine hemihydrate

Acta Cryst. (2008). C64, o649-o652 [doi.org/10.1107/S0108270108037086]

[Hydrogen bonding] Crystal packing in epialexine hemihydrate, showing hydrogen-bonding interactions which lead to the formation of a bilayered structure.
While determining the absolute and relative configuration of the natural product 1-epialexine, the Bijvoet pairs from data sets collected using both molybdenum and copper radiation were examined and compared using CRYSTALS . For the molybdenum data the Flack x parameter was refined to give an exceptionally large s.u. because there are no atoms heavier than oxygen. However, in contrast, the Hooft method suggests that the absolute configuration could be determined with a high confidence.

A.L. Thompson, D.J. Watkin, Z.A. Gal, L. Jones, J. Hollinshead, S.F. Jenkinson, G.W.J. Fleet and R.J. Nash