F. Florencio

The conformation of heterocyclic spiro compounds. II. The crystal and molecular structure of N-methylgranatanine-3-spiro-5'-hydantoin

Crystals of N-methylgranatanine-3-spiro-5-hydantoin, C ~,H ~7N302, are monoclinic, space group P21, with a = 13.889 (2), b = l 1.913 (1), c = 6.971 (1) A, fl = 93.56 (1) °, and four molecules in the unit cell. The structure was determined by direct methods and refined by Fourier and least-squares calculations. The bicyclo[ 3.3. I ]nonane system of the molecule adopts a flattened double-chair conformation.

The conformation of heterocyclic spiro compounds. VIII. 3,7-Dimethyl-3,7-diazabicyclo[3.3.1]nonane-9-spiro-5'-hydantoin

This structure determination is part of a study being carried out in this laboratory on heterocyclic spirohydantoin derivatives with pharmacological properties. The present compound was obtained by Trigo, Galvez & Avendafio (1978). The results of proton N M R studies seemed consistent with an adamantanelike structure, in agreement with Douglass & Ratliff (1968), Fig. 1. Support for this structure was derived from the position of the N-methyl resonance. However, the same authors admit that this fact does not constitute a definitive proof of this supposition. The present investigation was performed in order to verify the above statement and to elucidate the structure in the solid state.

The structure of N‐(γ‐hydroxypropyl)granatanine‐3‐spiro‐5'‐hydantoin monohydrate

C 1 3 H 2 1 N 3 0 3 . H 2 0 , monoclinic, P2~/n, a = 12.389(1), b = 12.108(1), c = 9 .213(1) A, fl = 93.80 (3) °, Z = 4, V = 1378.96 (6) Aa, Dx = 1.374, D m = 1.38 Mg m -s,/~(Cu Ka) = 0.80625 mm -~, 2 = 1.5418 A. The structure was solved by direct methods and refined to R = 0.052 for 2195 reflections. The bicyclol3.3.1lnonane system adopts a boat-chair conformation. The resolution of the structure confirms the interpretation of IR spectra which showed the quaternary character of the piperidine N atom. Introduction. Crystals of the title compound were supplied by Drs C. Avendafio and P. Ballesteros of the Departamento de Quimica Org~,nica y Farmac6utica de la Facultad de Farmacia de la Universidad Complutense de Madrid. A crystal of dimensions 0.25 × 0.30 × 0.20 mm was used to measure the unit-cell parameters and the intensity data on a Philips PW 1100 automatic diffractometer fitted with a graphitecrystal monochromator. An 09-20 scanning mode with Cu Ka radiation was used to measure 2638 independent reflections with 0 values below 65 o; 2195 of these were considered as observed [I > 2tr(I) where tr(I) was determined from counting statistics]. The intensity data were reduced to structure factors and no absorption correction was applied. The structure was solved with M U L T A N (Main, Woolfson, Lessinger, Germain & Declercq, 1977). 18 out of 20 atoms appeared on the E map calculated with 150 reflections. The two remaining atoms were located in a difference Fourier map. The structure was refined * The Conformat ion of Heterocyclic Spiro Compounds . X. t Granatanine is 9-azabicyclol3.3.1lnonane and hydantoin is 2,4-imidazolidinedione. by full-matrix least squares with isotropic and anisotropic thermal factors. All the H atoms, with the exception of the two water H atoms, were located in a difference map, and included only in one cycle of refinement with isotropic temperature factors. In successive cycles these temperature factors were kept fixed. The H atoms of the water were included at ideal positions in the first refinement and, in subsequent refinements, were kept fixed. The refinement continued to a stage at which no parameter shift was significant. The final R value was 0.052 and R w = 0.066 where R = ~[IFol IFcl[/~ IFol and R w = 1~ w(IFo[ IFcl)Z/~ IFolZ] lie. A weighting scheme was applied so as to give no trends in (wA 2) vs IFol and sin 0/2. The expression for the function of the weighting scheme is given in Table 1 (Martinez-Ripoll & Cano, 1975). No trend in sin 0/2 was observed. The atomic scattering factors used were taken from International Tables for X-ray Crystallography (1974). Computations were carried out with programs of the XRAY 70 system (Stewart, Kundell & Baldwin, 1970). Table 1. Function and coefficients for the weighting scheme w r = K / l f ( IFo l ) l 2, I / f (sin 0~2); K = 0 .673: f ( I F o l ) = a + blFol.