organic compounds
Open access
The title compound, C18H24N2O4·H2O {systematic name: (1aR,7aS,8R,10aS,10bS,E)-5-hydroxymethyl-8-[(1H-imidazol-1-yl)methyl]-1a-methyl-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one monohydrate}, an imidazole derivative of melampomagnolide B was synthesized under Michael addition conditions. The molecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings. The internal double bond of the ten-membered ring identifies it as the cis or E isomer. The lactone ring has an envelope-type conformation, with the (chiral) C atom opposite the lactone O atoms as the flap atom. In the crystal, O—HO, O—HN and weak C—HO hydrogen bonds link the molecules (along with water) into sheets parallel to the bc plane.
organic compounds
Open access
The title compound, C17H27NO3·0.08H2O {sytematic name: (3R,3aS,9R,9aS,9bS)-3-[(dimethylamino)methyl]-9-hydroxy-6,9-dimethyl-3,3a,4,5,7,8,9,9a-octahydroazuleno[4,5-b]furan-2(9bH)-one 0.08-hydrate}, exhibits intramolecular O—HO hydrogen bonding to form a ring of graph-set motif S(6). As well as this intramolecular hydrogen bond with the lactone-ring O atom, the hydroxy H atom forms an O—HO hydrogen bond to the low-occupancy partial water molecule [occupancy = 0.078 (2)]. The water molecule is correlated with disorder of the N(CH3)2 group [major–minor occupancy factors are 0.922 (2):0.078 (2)]. The dihedral angle between the mean planes of the trans-fused seven-membered ring and the lactone ring is 4.42 (9)°.