4a-Hydroxy-3,3,6,6-tetramethyl-9-[6-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)pyridin-2-yl]-2,3,4,4a,5,6,7,8,9,9a-decahydro-1H-xanthene-1,8-dione ethanol hemisolvate hemihydrate

The pyridine ring in the title compound, C39H47NO7·0.5C2H5OH·0.5 H2O, is connected to one 3,3,6,6-tetramethyl-1,8-dioxoxanthenyl and one 4a-hydroxy-3,3,6,6-tetramethyl-1,8-dioxodecahydroxanthenyl substituent in the 2- and 6-positions of the ring. In the former substituent, the six-membered xanthenyl ring adopts a flattened envelope conformation (with the methine C atom as the flap) while in the latter, the six-membered xanthenyl ring adopts a twisted envelope conformation (with the C atom bearing the hydroxy group representing the flap). The hydroxy H atom forms an intramolecular hydrogen bond to the pyridyl N atom. An ethanol solvent molecule is disordered with respect to a water molecule in a 1:1 ratio. The water molecule itself is disordered over two positions of equal occupancy.

The pyridine ring in the title compound, C 39 H 47 NO 7 Á-0.5C 2 H 5 OHÁ0.5 H 2 O, is connected to one 3,3,6,6-tetramethyl-1,8-dioxoxanthenyl and one 4a-hydroxy-3,3,6,6-tetramethyl-1,8-dioxodecahydroxanthenyl substituent in the 2-and 6positions of the ring. In the former substituent, the sixmembered xanthenyl ring adopts a flattened envelope conformation (with the methine C atom as the flap) while in the latter, the six-membered xanthenyl ring adopts a twisted envelope conformation (with the C atom bearing the hydroxy group representing the flap). The hydroxy H atom forms an intramolecular hydrogen bond to the pyridyl N atom. An ethanol solvent molecule is disordered with respect to a water molecule in a 1:1 ratio. The water molecule itself is disordered over two positions of equal occupancy.

Experimental
Amino-iso-propanol (20 mmol), pyridine-2,6-dicarboxaldeyde (10 mol) and dimedone (40 mmol) were heated in ethanol (100 ml) for 5 h. The solution was cooled and the brown solid collected and recrystallized from ethanol to give colorless crystals, m.p. 348 K. The synthesis did not yield the expected decahydroacridine derivative (in which the iso-propylamino group would replaced the ether oxygen of the xanthene unit).

Refinement
Carbon-and oxygen-bound H-atoms were placed in calculated positions [C-H 0.95 to 0.98 Å and O-H 0.84 Å; U iso (H) 1.2 to 1.5U eq (C,O)] and were included in the refinement in the riding model approximation.
The ethanol molecule is statistically disodered with respect to a water molecule As the occupancy refined to a nearly 1:1 ratio, the disordered was interpretated as a hemisolvate hemihydrate. For the ethanol molecule, the carbon-carbon distance was tightly restrained to 1.500±0.005 Å and the carbon-oxygen distance to 1.450±0.005 Å; the carbon···oxygen distance was restrained to 2.30±0.01 Å. The water molecule is disordered over two positions and the occupancies were fixed to 0.25.
The temperature factors of the disordered atoms were restrained to be nearly isotropic. The H-atoms of the disordered water components were placed in arbitrary positions.
supplementary materials sup-2 Figures Fig. 1. Thermal ellipsoid plot (Barbour, 2001) of C 39 H 47 NO 7 × 0.5 C 2 H 5 OH × 0.5 H 2 O at the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius. The disordered water molecules are not shown.