1. Studies on rearrangements in derivatives of grandiflorenic acid. Part 1. Reaction of the epoxides of methyl (–)-kaur-9(11)-en-19-oate and (–)-kaur-9(11)-en-19-oic acid with boron trifluoride-diethyl ether either in the absence or in the presence of N-nitrosomethylurea. Formation of two diterpenes of a new skeletal type
2. Diterpene vom kaurantyp aus der composite espeletia schultzii (wedd)
3. Structure of the antheridium-inducing factor of the fern Anemia phyllitidis
4. Crystal data for (2): C23H34O4,M, = 374.53, monoclinic, space groupP21,a, = 11.348(1) Å,b, = 8.118(1) Å,c, = 11.323(1) Å, β = 95.11(1)°,V, = 1039.0(3) Å3,Z, = 2,Dcalcd= 1.197 g cm−3, μ(Cu-Kα radiation, Δ = 1.5418 Å) = 6.0 cm−1. Intensity data (+h, + k $ l, θmax= 75°, 2290 non-equiv. refls.), were recorded on an Enraf-Nonius CAD-4 diffractometer (Cu-Kα radiation, graphite monochromator). the crystal structure was solved by direct methods (MULTAN11/82). Full-matrix least-squares refinement of atomic parameters (anisotropic C, O; isotropic H) converged atR, = 0.048 (Rw= 0.063) over 2095 reflections withI, > 3.0$(I). Atomic parameters for (2) have been deposited at the Cambridge Crystallographic Data Centre, Lensfield Road, Cambridge CB2 1EW.