Crystal and molecular structure of 1R,3S,5S,7R,10R-3,6,6,10,14-Pentamethyltricyclo[10.3.0.05,7]pentadeca-11,14-diene-1, 10-dihydroxy-2,13-dione (Japodagrol), C20H28O4

A new cytotoxic macrocyclic diterpenoid named Japodagrol, C₂₀H₂₈O₄, has been isolated from the ornamental plantJatropha podagrica, family Euphorbiaceae, grown in Nigeria. The structure of the title compound, C₂₀H₂₈O₄, was solved by X-ray analysis.M _r =332.44, monoclinic space groupC2,a=23.285(4),b=6.5105(12),c=12.505(3) Å,=98.504(17),V=1874.8 ų,Z=4,D _c =1.178 Mg/m³. CuK radiation (graphite crystal monochromator, =1.54184 A), (CuK)=6.13 cm^–1,F(000)=720,T=290 K. Final conventionalR factor=0.035,R _w =0.038 for 3349 observed reflections. The structure was solved with the programDirdif. The 5-membered ring is closed to a half-chair form. The compound contains inter- and intramolecular hydrogen bonds.     

Crystal and molecular structure of (exo)-2-phenyl-5-ethoxycarbonyl-4,5,6,11b-tetrahydroisoxazolidino-[2,3-a]-β-carboline,C22H22N2O3

The structure of the title compound, C₂₂H₂₂N₂O₃, was determined by X-rays atT=290 K.M _r =362.427, orthorombic, space groupPbca,a=11.666(4),b=15.691(1),c=20.931(1) Å,V=3831.4 ų,Z=8,D _x =1.257 Mgm^–3. CuK radiation (graphite crystal monochromator, =1.54178 Å),(CuK)=6.42 cm^–1. Final conventionalR-factor=0.050,R _w =0.062 for 2552 observed reflections and 301 variables. The structure was solved usingMultan.     

Crystal and molecular structure of 1-methyl-2,3,5,6-tetraphenylpiperidin-4-ol,C30H29NO

The structure of the the title compound, C₃₀H₂₉NO, was determined by X-rays.M _r =419.57, triclinic, space groupP1,a=5.8922(12),b=8.5855(11),c=12.2216(20) Å,=78.145(12)°,=79.181(15)°, =76.108(14)°,V _c =581.1(1) ų,Z=1,D _x =1.199 Mg m^–3. CuK radiation (graphite crystal monochromator, =1.54184 Å),(CuK)=5.17 cm^–1,T=290K. Final conventionalR-factor=0.039,R _w =0.042 for 2795 observed reflections and 377 variables. The structure was solved usingMultan andDirdif. With a view to determining the conformational preference of the piperidine ring when it is highly sustituted with a bulky group like the phenyl group, the present X-ray investigation was undertaken.