Novel manganese(III) oxidation chemistry: X-ray crystal structures of (1α,2α,4β)-1,2-diacetoxy-4-(4-methoxyphenyl)-6-methoxy-1,2,3,4-tetrahydronaphthalene (compound A) and (1α,2α,4β)-1,2-diacetoxy-4-(2-methoxyphenyl)-8-methoxy-1,2,3,4-tetrahydronaphthalene (compound B)

CompoundA is (1,2,4)-1,2-diacetoxy-4-(4-methoxyphenyl)-6-methoxy-l,2,3,4-tetrahydronaphthalene, C₂₂H₂₄O₆,M _r=384.43, monoclinic, P2₁/n, witha=11.074(3),b=10.353(4),c=17.616(4)Å,=94.96(2)°,V=2012.1ų,D _calc=1.27 g cm^–3 and=0.55 cm^–1 forZ=4. Least-squares refinement of 1371 observed [F ₀5 (F ⁰)] reflections led to the final agreement index ofR=0.052. A twofold disorder was observed for the 1-acetoxy group whereas the 2-acetoxy group was ordered. CompoundB, (1,2,4)-1,2-diacetoxy-4-(2-methoxyphenyl)-8-methoxy-l,2,3,4-tetrahydronaphthalene, C₂₂H₂₄O₆,M _r=384.43, crystallizes in the monoclinic space group, P2₁/c, witha=16.209(2),b=10.076(1),c=13.357(4)Å,=111.41(2)°,V=2030.9ų,D _calc=1.26 g cm^–3 and=0.54 cm^–1 forZ=4. A final agreement index ofR=0.045 was realized by least-squares refinement of 1486 observed [F _o5 (F _o)] reflections. Intermolecular interactions in the cell lattices of compoundsA andB are noted. The title compoundsA andB were prepared by manganese(III) acetate oxidative dimerization of two molecules of 4-methoxystyrene and 2-methoxystyrene, respectively.     

5-(thien-2-yl) uracil analogs: 5-(5-methylthien-2-yl)-2′-deoxyuridine, 5-(5-thien-2-yl)-2′-deoxyuridine,and 5-(5-bromothien-2-yl)-2′-deoxyuridine

Crystal structures of 5-(5-methylthien-2-yl)-2-deoxyuridine (I), 5-(5-thien-2-yl)-2-deoxyuridine (II) and 5-(5-bromothien-2-yl)-2-deoxyuridine (III) have been obtained from data collected on a four-circle Enraf-Nonius diffractometer (CAD-4 system). Space group, unit/cell parameters and finalR indices are:I, monoclinic,P2₁,a=9.105(2),b=20.819(2),c=7.932(2) Å, =98.79(2)°,R=5.7%;II, monoclinic,P2₁,a=8.720(4),b=20.793(4),c=7.884(4) Å, =95.06(2)°,R=5.8%;III, monoclinic,P2₁,a=9.260(2),b=41.655(7),c=7.926(2) Å, =97.996(13)°,R=9.4%. Structural properties of the title compounds are compared with those of 5-(5-chlorothien-2-yl)-2-deoxyuridine (IV) previously reported in order to explain their affinity for HSV-1 thymidine kinase and their eventual interaction with viral DNA polymerase. The main structural features observed are the coplanarity of the uracil and thienyl cycles stabilized by a S–O intramolecular interaction and the formation of dimeric intermolecular H bonds between two uracil moieties.     

Structure of (1αH,6βH,7αH,8αH)-1α,10α-epoxy-8β-hydroxy-germacr-2,11(13)-dien-6,12-olide (Incomptine B): A sesquiterpenoid lactone

C₁₅H₁₈O₄ is monoclinic,P2₁. Unit-cell dimensions at 293 K area=15.048(5),b=9.756(3),c=15.815(5)Å,=114.18(2)°,V=2118(1)ų,D _x=1.23 g cm^–3, andZ=6. The structure has been determined from single-crystal data collected with a four-circle diffractometer and refined from 2816 observed reflections toR=0.054. The structural features determined from chemical and spectroscopic studies are confirmed and extended. The incomptine B occurs as three independent molecules with different conformations. The stereochemistry at C(6), C(7), and C(8) is 6S, 7R, and 8R. The 10-membered ring has an approximate C₂ symmetry for the A, B, and C molecules. The -methylene -lactone ring adopts a half-chair conformation for molecule A, and a conformation intermediate between-envelope and half-chair for the B and C molecules, respectively. The structures are stabilized by a three-dimensional network of O-HO hydrogen bonds and several C-HO interactions.     

Crystal structure of (4α,4aα,8aα)-(±)-octahydro-2-(phenylmethyl)-2H-1,2-benzoxazin-4-ol, 4-methylbenzenesulfonate(ester)

The title compound, a bicyclic tetrahydro-1,2-oxazine, crystallizes in a monoclinic lattice, space group P2₁/c, with a = 12.9809(18)Å, b = 12.920(2)Å, c = 13.631(2)Å, = 110.713(12)°, and Z = 4. The structure found in the solid state for this conformationally mobile molecule shows the tosyl group in an axial position and a benzyl group in an equatorial position of the bicyclic system.     

The crystal and molecular structure of spiro[1-(S)-Br-3-(S)-H-4-(R)-l-(1′ R,2′ S,5′R)-menthyloxy-5-oxo-6-oxa-bicyclo[3.1.0]hexane-2,3′-(R)-(4′-(R)-diphenylmethoxy-5′-l-(1′ R,2′ S,5′ R)-menthyloxy-butyrolactone)]

Crystal structure of C₄₁H₅₃O₇Br has been determined by single-crystal X-ray diffraction. The compound crystalline in the orthorhombic space group P2₁2₁2₁, with a = 11.264(2), b = 12.058(2), c = 29.337(6) Å, Z = 4. The bond angles of cyclopropane moiety in the molecule are approximate to 60° and agree with theoretic values of the internal angles in a cyclopropane, and two chiral menthyloxy groups are located above and under the whole chiral molecule, respectively. The configuration of the pentacyclic lactone is shown as envelope form.     

Crystal structure of a (25R)-2α,3α-epoxy-5α-spirostan-6, 23-dione hemi-ethyl acetate solvate

The compound (25R)-2,3-epoxy-5-spirostan-6,23-dione, crystallizes as a hemi-ethyl acetate solvate, having two host molecules of similar conformation per molecule of ethyl acetate, in the asymmetric unit. The O atom of the epoxy group is -oriented. The presence of the epoxy group disturbs the chair conformation in the ring A of the steroidal nucleus. Ring A has a C5,C10 half-chair conformation. The six-membered rings B, C, and F have chair conformation as expected. The D ring adopts a C14-envelope conformation and the E ring is midway between a C22,O3 half-chair and a C22-envelope conformations. The A/B, B/C, and C/D ring junctions are trans. Crystal data: C₂₇H₃₈O₅·1/2C₄H₈O₂, Monoclinic, space group P2₁, a = 7.7363(18) b = 28.769(12) c = 12.038(6) Å, = 90.88(5), V = 2679.0(10) ų, Z = 4. The packing of the molecules is assumed to be dictated by van der Waals interactions and by intermolecular C—H ··· O hydrogen bonds.     

(20R,22R)-6α,7α-Epoxy-5α,27-dihydroxy-1-oxowitha-2,24-dienolide in Leaves of Withania somnifera: Isolation and its Crystal Structure

Abstract  (20R,22R)-6α,7α-Epoxy-5α,27-dihydroxy-1-oxowitha-2,24-dienolide (27-hydroxy-withanolide B) was isolated from Withania somnifera. The structure of the withanolide was established by spectral analysis and X-ray diffraction studies. The compound crystallizes in the orthorhombic space group P2₁2₁2₁ with unit cell parameters: a = 9.2163(3), b = 11.1828(4), c = 23.6146(9) ?, Z = 4. The crystal structure was refined to R = 0.0495 for 3,284 observed reflections. All the rings of the steroid skeleton are trans connected. Rings A and B exist in a half-chair conformation, ring C a chair, and five membered ring D is intermediate between a half-chair and an envelope. The δ-lactone ring E adopts a distorted sofa conformation. The twist along the length of the steroid nucleus is −6.5°. The characteristic pattern observed in the packing diagram is the appearance of twisted chains of molecules packed together to form layers. Index Abstract  Isolation and crystal structure analysis of (20R,22R)-6α,7α-epoxy-5α,27-dihydroxy-1-oxowitha-2,24-dienolide.      

[(2,3-O-Isopropylidene-5-O-(triphenylmethyl)-α-D-ribofuranosyl]-triphenylstannane

The synthesis, IR, MS, solution and solid state NMR spectra and X-ray structure of (2,3-O-isopropylidene-5-O-(triphenylmethyl)--D-ribofuranosyl]triphenylstannane 1 (R₃Sn) are reported. Compound, 1 (R₃Sn) crystallizes in the orthorhombic space group C222₁ (Z = 8), with a = 8.935(4), b = 17.058(7), c = 47.94(5)Å. There are two short tin–oxygen separations, at 3.030(7) [involving O4, on an alpha carbon] and 3.094(7) Å [involving O2, on a beta carbon]. Only the O4 atom is considered to form a weak and additional bond to tin; this results in a deviation of the geometry at tin toward trigonal bypramid from tetrahedral, with O4 and C34 in the axial sites [C34– Sn–O4=152.3(3)°]. The conformation of the ribofuranosyl ring in the solid state is E _o [P, the phase angle of pseudorotation, = 268.4(9)° and _max , the puckering amplitude, = 38.0(6)°], while the isopropylidene ring conformation is between the envelope form, E _C6, and the twist form, ^O3 T _C6 [P = 46.5(10)° and _max = 36.9(6)°]. In solution, the ribofuranosyl ring adopts a conformation between E _o and ¹ T _o.     

Crystal structure of 5-fluoro-1-(2,3,6-trideoxy-α-l-glycero-hex-2-enopyranos-4-ulosyl)uracil

The present compound crystallizes in the space groupP2₁2₁2₁ withZ=4 and cell parametersa=21.687(2),b=8.155(3),c=5.883(2)Å. The structure was solved by direct methods and refined by full-matrix least-squares to a finalR value of 0.045 for 1153 observed reflections. The N-glycosidic torsion angle _CN is in the anti-range and the pyranosyl ring adopts a distorted half-chair conformation with ₂=142.7(4)°, ₂=124.4(3)° andQ=0.456(2)Å. In the crystal packing the molecules are linked together by N-HO hydrogen bonds and C-HO contacts.     

Polymorphism in Dethoxyprone,a steroidal anesthetic. II. Crystal and molecular structure of 11α-dimethylamino-2β-ethoxy-3α-hydroxy-5α-pregnan-20-one (Dethoxyprone,form II)

The crystal and molecular structure of 11-dimethylamino-2-ethoxy-3-hydroxy-5-pregnan-20-one (Dethoxyprone, formII) (C₂₅H₄₃NO₃) has been determined by direct methods, and refined to a finalR of 0.067 for 4508 observed reflections. The compound crystallizes in space groupP2₁2₁2₁ with cell dimensionsa=10.830 (2),b=12.703 (2),c=17.490 (1) Å;Z=4,D _x =1.12 g cm^–3, (CuK )=5.28 cm^–1. The rings of the steroid skeleton are trans connected. Rings A, B, and C have chair conformations, while ring D has a half-chair conformation. The molecules are hydrogen bonded in a head to tail fashion through the hydroxy and keto groups.     

The crystal structure and IR spectra of μ-(bipyrimidine-N1,N1′,N5,N5′)-bis[(azido-N1)(methanol)(bipyrimidine-N1,N1′)copper(II)] bis(triflate) bis(methanol)

The structure of the title compound [Cu₂(bipym)₃(N₃)₂(CH₃OH)₂](CF₃SO₃)₂(CH₃OH)₂ has been determined by X-ray diffraction. The crystals are triclinic, space group P1, with a = 8.1844(5), b = 11.0253(6), c = 12.9089(7) Å, = 80.249(4), , = 74.933(5), = 74.001(4)°, and Z = 1. The structure consists of a dinuclear Cu(II) unit formed of two didentate bipym ligands, one bis-didentate bipym ligand, two azido anions, and two coordinating methanol molecules. The Cu(II) atom is elongated tetragonally surrounded by two nitrogens of the didentate bipym ligand, one nitrogen of the bis-didentate ligand, and one nitrogen of the azido anion forming the equatorial plane with one nitrogen of the bis-didentate ligand and an oxygen atom of the methanol molecule as the axial atoms. A noncoordinating triflate anion and an additional methanol molecule are also in the crystal lattice and have a hydrogen bond distance of 2.801(3) Å with an angle of 157(4)°. The cations link by O – H ··· N bonds into infinite chains running in the c-direction.     

Synthesis and Crystal Structure of 3-Quinuclidinyl α-(Cyclopentyl-1-ene)-α-hydroxy-α-phenylacetate

Abstract The title compound 3-quinuclidinyl α-(cyclopentyl-1-ene)-α-hydroxy-α-phenylacetate was obtained by the reaction of methyl α-(cyclopentyl-1-ene)-α-hydroxy-α-phenylacetate with 3-quinuclidinol in n-heptane. Its structure was characterized by ¹H, ¹³C NMR, MS and X-ray single-crystal diffraction techniques: C₂₀H₂₅NO₃, M _r = 327.41, orthorhombic, space group P2₁2₁2₁ with a = 8.547(2), b = 11.428(4), c = 18.288(5) ?, V = 1786.3(9) ?³, Z = 4. The title compound comprises a tertiary α-hydroxy acid and a bicyclo[2.2.2]octan moiety. The crystal structure shows the presence of the intermolecular O(1)–H(1)···N(1) hydrogen bonds. Index Abstract The title compound, 3-quinuclidinyl α-(cyclopentyl-1-ene)-α-hydroxy-α-phenylacetate was obtained by the reaction of methyl α-(cyclopentyl-1-ene)-α-hydroxy-α-phenylacetate with 3-quinuclidinol in n-heptane and its crystal structure determined. The title compound comprises a tertiary α-hydroxy acid and a bicyclo[2.2.2]octan moiety. The crystal structure shows the presence of the intermolecular O(1)–H(1)···N(1) hydrogen bonds.      

Structures of 8α-(2′-methylbutyryloxy)-9α-hydroxymontahibisciolide,a new skeletal type of sesquiterpene lactone,and of its precursor 8α-isobutyryloxy-9-oxo-germacra-4E, 1(10)Z-dien-6β,12-olide

The structures of a new skeletal type of sesquiterpene lactone, containing a seven, five, fivering system, and of its putative precursor, a 9-oxo-melampolide, have been confirmed by single crystal X-ray structure determination. The central 5-membered ring of the new skeleton istrans-fused to the cycloheptene ring andcis-fused to the lactone ring. Transannular interactions and the geometry of thetrans carbon-carbon double bond of the oxo-melampolide and the keto-group at C9, suggest that the new seven, five, five tricyclic skeleton-type of montahibisciolide can easily be reached by a transannular cyclization process. The isobutyrloxy group of the oxo-melampolide is disordered into two partially populated conformations. 8-(2-Methylbutyryloxy)-9-hydroxymontahibisciolide,3, C₂₀H₂₈O₅, crystallizes in orthorhombic space groupP2₁2₁2₁ witha=8.294(2),b=9.740(2),c=22.675(1) Å,V=1832(1)ų,Z=4. The structure was refined toR=0.043 andR _w=0.048 for 2898 observed reflections with CuK radiation. 8-isobutyryloxy-9-oxo-germacra-4E, 1(10)Z-dien-6, 12-olide,4, C₁₉H₂₄O₅, crystallizes in monoclinic space groupC2 witha=32.879(7),b=5.793(2),c=9.884(4)Å, =99.01(3)°,V=1859.5(9)å³,Z=4. The structure was refined toR=0.054 andR _w=0.064 for 1010 observed reflections with MoK radiation.     

Molecular structure and absolute configuration of (+)-(1R, 2S, 6R, 7S, 1′R)-5-(1′-phenylethylamino)-endo-tricyclo[5.2.1.02,6]deca-4,8-dien-3-one

The crystal and molecular structure of (+)-(1R, 2S, 6R, 7S, 1R)-5-(1-phenylethylamino)-endo-tricyclo[5.2.1.0^2,6]deca-4,8-dien-3-one is described. Based on the known absolute configuration (R) of the -phenylethylamine moiety the X-ray analysis revealed the absolute configuration of the title compound. The structure was refined to R ₁ = 0.0298 for 1950 reflections (with I > 2(I)). Crystal data: C₁₈H₁₉NO, monoclinic, space group P2₁, a = 6.7406(4), b = 9.959(2), c = 11.3123(8)Å, = 102.969(5), V = 740.0(2)ų, and Z = 2.     

Crystal structure and charge distribution for 20 oximino-5α-pregn-16-eno[3, 4,-c]-1′2′5′-oxadiazole (HS998)

The crystal structure of the modified steroid, 20 oximino-5 pregn-eno [3, 4-c] 125 oxadiazole (HS998) using X-ray diffraction is reported. HS998 crystallizes in the orthorhombic space groupP2₁2₁2₁, having cell parametersa=13.465(3),b=18.792(4),c=7.598(2) Å;Z=4. The structure was solved by direct methods and refined by full matrix least squares toR=0.060 for 3478 reflections.     

Conformational Studies of Substituted Chromans: Crystal Structures of 2,2′-(1E,1′E)-(2,3-Dimethylchroman-2,4-diyl)bis(Azan-1-yl-1-ylidene)bis(Methan-1-yl-1-ylidene)Diphenol (I) and 2,2′-(1E,1′E)-(2-Ethyl-3-Methylchroman-2,4-diyl)bis(Azan-1-yl-1-ylidene)bis(Methan-1-yl-1-ylidene)Diphenol (II)

Abstract  

The title compounds C₂₅H₂₄N₂O₃ (I) and C₂₆H₂₆N₂O₃ (II) crystallize in the triclinic space group P-1 with cell parameters a = 8.981(1), b = 9.933(1), c = 12.369(2) ?, α = 78.537(2), β = 84.515(2), γ = 73.561(2)° Z = 2 (I) and a = 11.4630(9), b = 12.955(1), c = 16.154(1) ?, α = 70.425(1), β = 87.403(1), γ = 71.850(1)°, Z = 4 (II). In both compounds the phenolic groups in the Schiff base substituents form intramolecular hydrogen bonds with the imine nitrogen atoms thereby rendering these substituents nearly planar. A detailed analysis of the amount by which the heterocyclic ring deviates from planarity (extent of puckering) in these and a series of related molecules shows that the extent of the deviation is largely unaffected by the number, size and placement of substituents on this ring.     

Crystal Structure of 9α,11-Epoxy-7α-(methoxycarbonyl)-3-oxo-17α-pregn-4-ene-21,17-carbolactone

Abstract  The title compound (common name eplerenone), C₂₄H₃₀O₆, is an aldosterone receptor antagonist. From the isopropyl acetate solution the compound crystallizes in monoclinic space group P 21 with a = 8.811(1) ?, b = 11.250(1) ?, c = 11.079(1) ?, β = 93.822(12)°, Z = 2. The molecule contains three six membered rings, two five membered rings and one three membered ring. Both five membered rings display envelope conformation, whereas three six membered rings show different conformation: chair, half-chair and envelope. In the crystal the eplerenone molecules link to one another via intermolecular weak C–H···O hydrogen bonding to form the smaller cavity of 12.0(1) ?³ between eplerenone molecules, no solvent molecule filled in this cavity. Index Abstract  In the title molecule three six-membered rings show different conformation. Weak C–H···O hydrogen bonding links adjacent molecules to form the small cavity 12.0(1) ?³, no solvent molecule filled in the cavity.      

Heterocyclic tautomerism. XI. Structures of 5,5′-bitetrazole and 1-methyl-5-(2′-pyridyl)tetrazole at 130 K

The X-ray crystal structures of 5,5-bitetrazole and 1-methyl-5-(2-pyridyl)tetrazole at 130 K are described. 5,5-Bitetrazole exists as the 1 H, 1'H-tautomer and packs in chains held together by pairs of intermolecular hydrogen bonds. It crystallizes in the monoclinic space group P2₁/n witha=4.945(1),b=6.367(1),c=8.491(1) Å and =99.233(7)^o. In 1-methyl-5-(2-pyridyl)tetrazole the two heterocyclic rings are nearly coplanar and the molecular packing is controlled by intermolecular – interactions. It crystallizes in the triclinic space group P1 witha=6.667(1),b=7.135(1),c=9.202(1)Å, =89.59(1), =69.08(1), and =66.62(1)^o.     

2α-Hydroxy-3α-[N-alkyl(aryl)]-pinanoamines. Part II. Synthesis and the nature of some pinanoamines and crystal and molecular structure of 2α-hydroxy-3α-(N-n-butyl)-pinanoamine hydrochloride

Several optically pure representatives of 2-hydroxy-3-[N-alkyl (aryl)] pinanoamines, potential chiral auxiliaries in organic synthesis, were obtained. In addition, a structural examination of 2-hydroxy-3-(N-n-butyl)-pinanoamine hydrochloride was conducted. Results of these studies confirm the structure of the amines obtained and the correctness of the proposed reaction pathway.Crystal data: C₁₂H₂₈NOCl,P2₁/c,a=13.196(1),b=8.562(1),c=14.276(1) Å,=110.41(3)°,R=0.034 for 2046 reflections.Part I,J. Cryst. Spec. Res. (1989)19, 535.     

Synthesis and Structure of 1-Chlorosulfonyl-2-(4′-Nitrophenoxy)-5-Methylbenzene

Abstract  Diphenyl ethers are structural elements found in medicinally useful antibiotics such as vancomycin as well as in biological toxins in the environment such as dioxins. The purpose of this paper is to report the synthesis and characterization of the previously unreported 1-chlorosulfonyl-2-(4′-nitrophenoxy)-5-methylbenzene, a trisubstituted diphenyl ether derivative. ¹H NMR (CDCl₃) δ 2.45 (3H, methyl₅, s), 7.07 (1H, H₄, d, J ~8.27 Hz), 7.13 (2H, H_2′, H_6′, d, J ~9.0 Hz), 7.54 (1H, H₃, d, J ~8.28 Hz), 7.87 (1H, H₆, s), 8.22 (2H, H_3′, H_5′, J ~9 Hz); ¹³C NMR (CDCl₃) δ 20.7, 118.2, 121.9, 126.0, 129.8, 135.2, 135.8, 137.8, 143.8, 150.3, 161.4. An X-ray analysis has provided valuable insight into the effect of steric factors on the three dimensional shape of this compound which serves as a useful advanced intermediate in the synthesis of these biologically active molecules. A multistep synthesis of this molecule has been designed by retrosynthetic analysis as part of an ongoing program aimed at a function-oriented, multi-step economical synthesis of vancomycin lead antibiotics. Crystals are triclinic, space group P-1, a = 7.6537(15), b = 8.976(2), c = 11.050(2) ?, α = 67.645(11), β = 79.735(11), γ = 87.798(10)°, V = 690.5(2) ?³, Z = 2. Graphical Abstract  The synthesis and characterization of the previously unreported trisubstituted diphenyl ether derivative are reported. The phenyl rings form a dihedral angle of 64.49(4)° and the chlorosulfonyl group has a C–C–S–Cl torsion angle of 62.95(11)°.