Structures of Five \u3cem\u3etrans\u3c/em\u3e-2-Hydroxy and \u3cem\u3etrans\u3c/em\u3e-2-Methoxy-2-methyl-3,4-dihydro-4-aryl- 2\u3cem\u3eH\u3c/em\u3e,5\u3cem\u3eH\u3c/em\u3e-pyrano[3,2-\u3cem\u3ec\u3c/em\u3e]benzopyran-5-ones

Derivatives of 2-methyl-3,4-dihydro-2H,5H-pyrano[3,2-c][1]benzopyran-5-one. (1) Racemic trans-methoxy-4-phenyl, Mr = 322·4, monoclinic, P21/n, a = 5·858 (1), b = 16· 732 (9), c = 16·383 (9) Å, β = 94·82 (3)°, V = 1600·1 Å3, Z = 4, Dx = 1·338 g cm-3, λ(Mo Kα) = 0·71073 Å, μ = 0·866 cm-1, F(000) = 680, T = 298 K, final R = 0·047 for 1513 intensities. The trans methyl ketal of warfarin (C20H18O4) contains a half-chair dihydropyran ring distorted toward the d,e-diplanar conformation. (2) Resolved (2R,4R)-trans-2-methoxy-4-phenyl, Mr = 322·4, orthorhombic, P212121, a = 11·521(1), b = 14·061 (2), c = 10·055(2) Å, V = 1628·9 Å3 , Z = 4, Dx= 1·314 g cm-3, λ(Mo Kα) = 0·71073 Å, μ = 0·851 cm-1, F(000) = 680, T = 298 K, final R = 0·056 for 1660 intensities. The trans methyl ketal (C20H18O4) from R(+)-warfarin; its dihydropyran ring is a half- chair distorted toward the d,e-diplanar conformation. (3) Resolved trans-2-hydroxy-4-(4-methoxyphenyl), Mr = 338·4, orthorhombic, P212121, a = 10·584 (1), b = 10·621(5), c = 14·778 (2) Å, V = 1661·2 Å3, Z = 4, Dx = 1·353 g cm-3, λ(Mo Kα) = 0·71073 Å, μ = 0·908 cm-1, F(000) = 712, T = 298 K, final R = 0·044 for 1165 unique intensities. Compound C20H18O5 spontaneously resolves on crystallization from acetone and water, and absolute configuration of data specimen was not determined. It has a dihydropyran ring with a half-chair conformation; hydroxyl and lactone carbonyl are intermolecularly H-bonded at O···O = 2·79 Å. (4) Racemic trans-2-hydroxy-4-(2-methyl-6-methoxyphenyl), Mr = 372·4, monoclinic, P21/n, a = 9·637 (2), b = 14·345 (4), c = 13·224 (2) Å, β = 91·09 (1)°, V = 1827·8 Å3, Z = 4, Dx = 1·353 g cm-3, λ(Mo Kα) = 0·71073 Å, μ = 0·961 cm-1, F(000) = 784, T = 298 K, final R= 0·048 for 2339 unique intensities. A synthetic derivative of warfarin, it crystallizes as the hydrate C20H18O6.H2O and has a dihydropyran ring with a half-chair conformation and intermolecular H bonds with O···O distances between 2·67 and 2·77 Å. (5) Racemic trans-2-hydroxy-4-(4-dimethylaminophenyl), Mr = 369·4, triclinic, PĪ, a = 9·066 (3), b = 9·509 (2)°, c = 12·681 (3) Å, α = 98·50 (2), β = 91·25 (3), γ = 116·96 (2)°, V = 958·8 Å3, Z = 2, Dx = 1·279 g cm-3, λ(Mo Kα) = 0·71073 Å, μ = 0·854 cm-1, F(000) = 392, T = 298 K, final R = 0·045 on 2773 unique intensities. A synthetic derivative of warfarin, it also crystallizes as a hydrate, C21H21NO4.H2O, and has a dihydropyran ring with a half-chair conformation and intermolecular H bonds with O···O distances between 2·70 and 3·07 Å