Structural study of the molecular complex in crystals of brucine with pantolactone

We have determined an X-ray crystal structure, a = 12.482(1), b = 14.349(1) , c = 14.342(1) Angstrom, orthorhombic, P2(1)2(1)2(1), for a molecular comp lex of brucine with pantolactone. The crystal structure is composed of corr ugated sheets of brucine molecules containing the guest pantolactone molecu les. The conformational twist of the pyrrolidine ring in brucine may probab ly be important in projecting the amine N2 to provide a strong and specific binding site for a chiral complexation. The pseudo-equatorial orientation of the hydroxyl group of the pantolactone anchors itself for binding via hy drogen bonding. In the crystal packing, the pantolactone molecules form hel ices and the brucine molecules are attached to these helices by O-H ... N h ydrogen bonds.