Synthesis and crystal structure of bis(2,2′-bipyridyl)mononitritozinc(II) perchlorate. An example of a six-coordinate cis-octahedral ZnN4O2 chromophore

The crystal structure of bis(2,2-bipyridyl)mononitritozinc(II) perchlorate, [Zn(bipy)₂ (ONO)][ClO₄] (1) has been determined. The complex is monoclinic, with a = 10.9195(4) Å, b = 12.2320(5) Å, c = 16.5477(8) Å, = 105.6150(10), P2₁/n space group, with final R1 = 0.0657 and wR2 = 0.1630. The complex involves a [Zn(bipy)₂ (ONO)]⁺ cation and a [ClO₄]^– anion. The ZnN₄O₂ chromophore is six-coordinate, with a cis-distortion of the two oxygens of the nitrite, O(1) and O(2), at distances 2.216(5) and 2.197(5) Å from the zinc (Zn– O _mean = 2.206(5) Å, O = 0.019(5) Å) and two out of plane Zn–N bonds, Zn–N(2) and Zn–N(3), at 2.129(4) and 2.135(4) Å (Zn–n _mean/out = 2.132(4) Å, n _2,3 = 0.006(4) Å). The two inplane nitrogens, N(1) and N(4), at distances Zn–N(1) = 2.090(4) and Zn–N(4) = 2.085(4) Å (Zn–n _mean/in = 2.087(4) Å, n _1,4 = 0.005(4) Å) are greater than 2.0 Å, but slightly shorter than the axial bonds. The inplane angles ₁, ₂, and ₃ in 1 have values 150.33(18), 108.98(17), and 99.73(18) respectively. The stereochemistry is cis-distorted octahedral, with an ₃ = 99.37(18), which is lower than ₃ = 103.4(1) observed in [Zn(bipy)₂(ONO)][NO₃] (5). Comparison with the corresponding [Cu(bipy)₂(ONO)][Y] complexes suggested that the cis-distortion of the CuN₄O₂ chromophore in the copper(II) series does not originate in the Jahn–Teller or pseudo-Jahn–Teller effect.     

A comparison of the coordination preferences of Zn, Co, and Cd(II) with the heteroscorpionate ligand (2-hydroxy-3-t-butyl-methylphenyl)bis (3,5-dimethylpyrazolyl)methane

Reaction of the Zn, Cd, or Co nitrate salts with the deprotonated ligand (2-hydroxy-3-t-butyl-methylphenyl)bis(3,5-dimethylpyrazolyl)methane (L1O^–) in methanol produced the following complexes: [(L1OH)Zn(NO₃)₂] in two isomorphs, a = 40.983(8) Å, b = 9.571(2) Å, c = 15.667(8) Å, = 90, = 106.38(1), = 90, C2/c, and a = 13.027(3) Å, b = 14.781(4) Å, c = 16.107(3) Å, = 90, = 105.30(1), = 90, P2₁/n; [(L1OH)Cd(pz)(NO₃)₂] a = 14.7476(2) Å, b = 13.5411(2) Å, c = 16.7223(2) Å, = 90, = 110.3840(10), = 90, P2₁/c; and [(L1O)Co(pz)(NO₃)] a = 11.4240(2) Å, b = 13.4498(2) Å, c = 13.8056(2) Å, = 105.2080(10), = 105.8130(10), = 112.7470(10), P . The Zn adopts a pseudotetrahedral four-coordinate geometry where the potentially tridentate ligand is actually bidentate with a protonated and uncoordinated phenoxy arm. The Co complex is pseudooctahedral six-coordinate where the phenoxy arm is deprotonated and coordinated. Finally the Cd complex is seven-coordinate but the metal is not coordinated through the phenoxy group that is again protonated.     

Hydrogen-bond networks in the mono- and diprotonated cyclic diamine [9]aneN2S

The hydrogen-bond networks in the mono- and diprotonated cyclic diamine, 1-thia-4,7-diazacyclononane, [9]aneN₂S, have been examined. Crystals of the monoprotonated, form [9]aneN₂S HCl, contain a ribbon-like network of alternating strong and weak intermolecular N H Cl hydrogen bonds and weak intramolecular N H N hydrogen bonds. Crystal data for [9]aneN₂S HCl: monoclinic, a = 6.6640(6) Å, b = 10.3493(9) Å, c = 6.9807(6) Å, = 108.847(1)°, V = 455.63(7) ų, space group P2₁, Z = 2. In the di-protonated form, [9]aneN₂S 2HBr, the ribbon-like network comprises strong intermolecular and weak intramolecular N H Br hydrogen bonds. Crystal data for [9]aneN₂S 2HBr: orthorhombic, a = 12.5918(13) Å, b = 8.0753(9) Å, c = 10.6856(11) Å, V = 1086.5(2) ų, space group Pnma, Z = 4. The chloride anions of [9]aneN₂S HCl align in interlocking columns in the a- and c-direction whereas the bromide anions in [9]aneN₂S 2HBr occupy channels in the b-direction.     

Structure of bis(2-amino-5-methylpyridinium) tetrachlorozincate at 298 and 150 K

Reaction of 2-amino-5-methylpyridine with zinc chloride and HCl in aqueous solution yields bis(2-amino-5-methylpyridinium) tetrachlorozincate. The complex crystallizes in the monoclinic space group P2₁/c, with minimal tetrahedral distortion of the ZnCl₄ ^2– ion at both 298 and 150 K; at 298 K, a = 8.090(2) Å, b = 14.795(6) Å, c = 15.850(4) Å, = 101.93 (2); at 150 K, a = 8.0986(2) Å, b = 14.7190(5) Å, c = 15.7684(7) Å, = 102.862(2). The anisotropic cell contraction results in significant changes in nonbonding Cl Cl contacts.     

Crystal and molecular structures of quinazolines: A ring conformational study

The solid state structures of two dihydropyrimidines (DHPM) viz, 2-[(4-dimethylamino)phenyl]-1-phenethyl-2,3-dihydro-1H-quinazolin-4-one (compound 1) and 1-phenethyl-2p-tolyl-2,3-dihydro-1H-quinazolin-4-one (compound 2) are reported here. The compound 1 belongs to triclinic (P-1) space group with cell parameters a = 7.4314(12) Å, b = 9.9747(16) Å, c = 14.658(2) Å, = 104.142(3), = 102.584(3), = 98.188(3). The compound 2 also belongs to triclinic (P-1) space group with cell parameters a = 9.8707(11) Å, b = 9.9225(11) Å, c = 10.7425(13) Å, = 79.227(2), = 80.568(2), = 63.649(2). The structures show that the substituent at 2-position will play a key role in defining the pyrimidine ring conformation. The central dihydropyrimidine ring in both the structures are affected by conjugation. The sum of the valence angles around all the nitrogens is very close to 360, indicating that the state of hybridization of these atoms is sp². The DHP ring is puckered in such a manner that the atoms N1, C3, C4, C5, and N2 are coplanar and the sixth atom C2 is displaced 0.605 Å (0.18 Å for compound 2) above the least squares plane. The conformation of dihydropyrimidine ring can be described as a sofa with asymmetric parameters C_s[C2] = 6.09 (compound 1) and 4.73 (compound 2), respectively. The phenethyl group has a fully extended conformation with respect to the central pyrimidine ring (N2–C16–C17–C18 174.8(2) and 179.1(6) for compounds 1 and 2, respectively). The substituents on the DHPM ring, dimethylamino-phenyl/p-tolyl groups of compound 1/2 occupy equatorial/axial positions at C2. In the crystal packing, six membered rings form through dimerization using N–HO hydrogen bonding.     

Crystal structure,physical and photophysical properties of a platinum(II) complex coordinated to the biphenyl dianion and cyclooctadiene

The complex, Pt(bph)(COD), where bph is the biphenyl dianion and COD is 1,5-cyclooctadiene, crystallizes in the orthorhombic space groupPbca witha=12.178(4) Å,b=9.693(3) Å andc=25.344(9) Å andZ=8. The Pt–C distances to the olefinic carbon atoms that result from the electron donation of the COD ligand are in the range 2.20(3)–2.27(3) Å and the Pt–C distances to the bonded bph ligand are shorter at 2.01(3)–2.03(2) Å. The lowest energy absorption of the complex is at 383 nm (=1.2×10³). The emission spectrum is structured in fluid solution at room temperature with the emission energy maximum at 537 nm, _cm, and =1.93 s. Temperature dependent emission lifetime measurements result in ak _o value of 2.69×10⁴, a preexponential factor of 2.47×10⁶ and a E₁ value of 324 cm^–1.     

Ethyl 1,2,3,4-tetra-O-acetyl-β-D-glucopyranuronate

The crystal structure, at 120 K, and solution ¹H and ¹³C NMR spectra of ethyl 1,2,3,4-tetra-O-acetyl--D-glucopyranuronate, (8) have been determined. Compound 8 crystallizes in the triclinic space group, P1 (Z = 1) with a = 6.0209(3) Å, b = 8.9698(5) Å, c = 9.9818(8) Å, = 104.965(2)°, = 98.522(3)°, = 106.790(5)°. The Cremer and Pople puckering parameters [Q = 0.602(4) Å, = 7.1(4)°, = 325(3)°] for the pyranose ring in the solid state indicate a near ideal ⁴C₁ chair conformation with a slight distortion in the direction towards ⁰H₅. A number of weak, soft intermolecular C–H O hydrogen bonds set up a 3D array. NMR spectra and FAB and EIMS data have been obtained. Solution NMR parameters suggest that the solid state conformation is maintained in solution in chloroform.     

Syntheses and structures of dihydrocalix[4]arenes bearing O-benzonitrile and O-acetonyl substituents

Three 25,27-dihydrocalix[4]arene derivatives, bearing benzonitrile and acetone groups on the oxygens, were prepared and structurally characterized. All three structures crystallize in , with cell dimensions: bis(benzonitrile)calix[4]arene·toluene, a = 11.530(2) Å, b = 12.013(2) Å, c = 14.089(4) Å, = 103.555(18)°, = 94.341(18)°, = 104.704(16)°, and V = 1815.9(7) ų; anti-bis-acetone-calix[4]arene, a = 7.5847(8) Å, b = 12.0948(17) Å, c = 15.3375(16) Å, = 78.982(10)°, = 76.932(9)°, = 73.129(10)°, and V = 1299.6(3) ų; syn-bis-acetone-calix[4]arene, a = 9.080(3) Å, b = 10.391(3) Å, c = 14.816(3) Å, = 96.998(19)°, = 100.02(2)°, = 103.93(3)°, and V = 1299.6(3) ų.     

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.     

Synthesis and crystal structure of 3,5-di(2-propenyl)-6-phenyl-1,3,5-triazine-2,4-dione and 2-dimethylamino-4-ethoxycarbonylmethoxy-6-phenyl-1,3,5-triazine

The title compound 3,5-di(2-propenyl)-6-phenyl-1,3,5-triazine-2,4-dione has been synthesized by the reaction of 6-phenyl-1,3,5-triazine-2,4-dione with allyl bromide. Its structure was determined by X-ray single crystal diffraction. The crystal belongs to orthorhombic, space group Pbca with the following crystallographic parameters: a = 16.282(4) Å, b = 8.888(2) Å, c = 19.281(5) Å, = 90°, = 90°, = 90°, = 0.088 mm^–1, V = 2790.1(13) ų, z = 8, Dx = 1.282 mg/m³, F(000) = 1136, T = 293(2) K, 2.11° 25.02°, the final R factor: R ₁ = 0.0430, wR₂ = 0.0981. The X-ray results demonstrate that the reaction of 6-phenyl-1,3,5-triazine-2,4-dione with allyl bromide in the presence of N,N-dimethylformamide and potassium carbonate yields the N-alkylated product. The title compound 2-dimethylamino-4-ethoxycarbonylmethoxy-6-phenyl-1,3,5-triazine has been synthesized by a new reaction, in which the solvent N,N-dimethylformamide involves. Its structure was determined by X-ray single crystal diffraction. The crystal belongs to triclinic, space group P-1 with the following crystallographic parameters: a = 7.977(2) Å, b = 10.394(3) Å, c = 10.837(3) Å, = 111.774(5)°, = 104.050(5)°, = 99.446(5)°, = 0.093 mm^–1, V = 776.6(4) ų, z = 2, Dx = 1.293 mg/m³, F(000) = 320, T = 293(2) K, 2.14° 25.03°, the final R factor: R ₁ = 0.0582, wR ₂ = 0.1399. The distance of N(4) C(2) (1.339 Å) is much shorter than the length of normal C N (1.47 Å) and very close to that of C-N (1.33 Å), which is indicative of the significant double bond character.     

Synthesis and crystal structure of N-<Emphasis Type="Italic">tert-</Emphasis>butyl-N′-thio [O-(1-methylthioethylimino)-N″-methylcarbamic acid]-N,N′-dibenzoylhydrazine

The novel compound N-tert-butyl-N-thio[O-(1-methylthioethylimino)-N-methyl carbamic acid]- N,N-dibenzoylhydrazine has been synthesized by the reaction of N-tert-butyl-N,N-dibenzoylhydrazine with N-sulfenyl chloride of O-(1-methylthio ethylimino) -N-methylcarbamic acid. Its structure was determined by X-ray single crystal diffraction. The crystal belongs to monoclinic, space group P2₍₁₎/n with the following crystallographic parameters: a = 7.569(3) Å, b = 20.585(7) Å, c = 16.347(5) Å, = 90, = 92.606(6), = 90, V = 2544.4(14) ų, z = 4, Dx = 1.276 mg/m³, F(000) = 1032, T = 293(2) K, 2.34 25.01, the final R factor: R₁ = 0.0475, wR₂ = 0.0907. The N–N bond adopts a gauche conformation with a dihedral angle() of 98.8 for C(17)=N(1)=N(2)=C(7), whereas its parent compound N-tert-butyl-N,N-dibenzoyl hydrazine has the dihedral angle of –71.8.     

Crystal structure of a salt of the pyridinium-pyridine ion by X-ray and neutron diffraction

The crystal structure of [(C₅H₅N)₂H]⁺[ZnBr_3/2Cl_3/2(C₅H₅N)]^– has been determined and refined by full-matrix least-squares methods using X-ray (R, on ¦F _o¦, = 0.045 with 2291 reflections) and neutron (¯R, on ¦F _o¦, = 0.035 with 2030 reflections) diffraction data. The crystals of the compound are monoclinic, space groupP2₁/c witha = 12.728(1),b = 11.600(1),c = 13.354(1) Å, = 107.38(1) °,Z = 4,D _x = 1.68, andD _m(flotation) = 1.69 g cm^–3. The X-ray and neutron intensities were measured by the counter -2 scan technique with CuK X-rays ( = 1.5418 Å) and neutrons with = 1.109 Å, respectively. An intramolecular N--H hydrogen bond holds pairs of pyridine molecules together in the lattice [N N, 2.737(3) Å]. The hydrogen atom is very asymmetrically disposed with N-H distances of 1.086(7) Å and 1.658(6) Å. The coordination about the zinc atom is tetrahedral with the nitrogen atom of the pyridine molecule in one tetrahedral position and different mixtures of the two halogen atoms in the other three positions. The important average bond distances from the neutron study are Zn-N [2.073(3) Å], Zn-Cl [2.251(2) Å], Zn-Br [2.394(3) Å], N-C [1.334(5) Å], C-C [1.378(5) Å], and C-H [1.075(7) Å].     

Synthesis,characterization and crystal structure of oxovanadium(IV) complex with tridentate o-van-gly and bidentate phenanthroline

A novel oxovanadium(IV) complex with tridentate schiff base and bidentate phenanthroline ligands, VO(o-van)(phen) 2H₂O[o-van-gly: o-vanillin-glycine; phen: phenanthroline], was synthesized and characterized by elemental analysis, IR and UV-vis spectra. The crystal structure was determined by X-ray single crystal diffraction analysis. The crystal of title complex (C₂₂H₂₁N₃O₇V, M_w = 490.36) belongs to triclinic, space group P-1 with the following crystallographic parameters: a = 9.247(3) Å, b = 10.125(4) Å, c = 13.100(5) Å, = 106.343(6), = 96.042(7), = 101.726(7), V = 1135.0(7) ų, Z = 2, D_c = 1.435 Mg m^–3, (MoK = 0.485 mm^–1, F(000) = 506, and final R₁ = 0.0779, wR₂ = 0.1598 for observed reflections 1606 (I > 2(I)). V(IV) is six-coordinate with three oxygen atoms and three nitrogen atoms in a distorted octahedral geometry. The complex forms a 3-D network via – stacking and hydrogen bonds.     

Synthesis and structure of 4-R,5-R-[5-(hydroxy-diphenyl-methyl)-2, 2-dimethyl-[1,3]dioxolan-4-yl]-phenyl-methanone, a chiral ligand building block

A triphenyl analog of taddol, 4-R,5-R-[5-(hydroxy-diphenyl-methyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-phenyl-methanone, has been synthesized and structurally characterized. This molecule could act as a chiral ligand building block in the creation of tuned taddol analogs. Structural analysis of the title compound reveals that the hydroxyl group is involved in an intramolecular hydrogen bond and does not take part in any intermolecular interaction. Crystal packing is influenced by C–H O hydrogen bonding and phenyl phenyl interactions. Crystal data: Triclinic, P1 (No. 1), a = 5.9343(4) Å, b = 8.2367(17) Å, c = 10.987(2) Å, = 88.290(6), = 75.442(4), = 80.655(6), V = 512.86(15) ų, Z = 1, D _calc = 1.258 mg/m³. Final residual values were R ₁ = 0.0407 for 3022 observed data (I > 2s(I) ) and wR ₂ = 0.0941 for all 3524 unique data.     

Synthesis and crystal structure of 1-(1′,3′-dimethyl-5′-chloropyrazol-4′-carbonyl′-3-(2′-chlorophenyl)-5-amino-4-cyanopyrazole

The title compound 1-(1,3-dimethyl-5-chloropyrazol-4-carbonyl)-3-(2-chlorophenyl)-5-amino-4-cyanopyrazole (C₁₆H₁₂Cl₂N₆O) has been synthesized and characterized by X-ray diffraction: Triclinic, space group P1, with a = 8.6712(8) Å, b = 9.5091(10) Å, c = 11.2170(11) Å = 71.531(2)°, = 84.683(2)°, = 74.099(2)° Z = 2; V = 843.7(14) ų. C(10), O(1), C(11), and N(2) atoms are coplanar with the average deviation of 0.0071 Å, which form 11.03° and 43.93° dihedral angles with pyrazole planes (I) and (II), respectively.     

Crystal structures of two thienyl analogs of benzil – 1,2-dithien-2-ylethanedione (2,2′-thenil) and 1,2-dithien-3-ylethanedione (3,3′-thenil)

2,2-Thenil crystallizes in P2₁/c with a = 7.2501(12) Å, b = 4.7846(8) Å, c = 13.9867(23) Å, = 96.897(3), V = 481.67(14) ų, and Z = 2. The molecule resides on an inversion center and is planar. 3,3-Thenil also crystallizes in P2₁/c with a = 3.9904(8) Å, b = 21.310(4) Å, c = 11.618(2) Å, = 101.83(3), V = 966.9(3) ų, and Z = 4. Refinement of 3,3-thenil data indicated that 10.3(2)% of both thienyl rings are flip-disordered in this nonplanar molecule. A brief discussion of disorder in molecules containing terminal, unsubstituted 2- and 3-thienyl rings is presented.     

Crystal structure and conformation of N-(t-butoxycarbonyl)-L-isoleucyl-L-alanine benzylester

C₂₂N₂O₅H₃₂,M _r =404.5, monoclinic,C2,a=21.781(5),b=5.065(1),c=22.333(4)Å,=112.81(2)°,V=2271.1(9)ų,D _calc=1.148 g cm³, (CuK )=1.5418 Å,=5.89 cm^–1,F(000)=848, room temperature,R=0.058 for 2178 unique reflections [I2.5(I)]. The peptide linkage is in thetrans conformation. The molecule adopts the-sheet structure. The crystal structure is stabilized by a three-dimensional network of N-HO and C-HO hydrogen bonds.DCB Contribution No. 813.     

Bis(2,6-(2′,6′-diisoproylanil)diformyl-4-chloro-phenolate) nickel(II)

Bis(2,6-(2,6-diisoproylanil)diformyl-4-chloro-phenolate) nickel(II) was prepared by the reaction of 2,6-(2,6-diisoproylanil)diformyl-4-chloro-phenol with nickel chloride. The title complex crystallized in P2₁/c, with cell dimensions a = 9.962(2) Å, b = 12.087(3) Å, c = 24.445(6) Å, and = 97.032(5), giving a volume of 2921.4(13) ų. The bis(2,6-(2,6-diisoproylanil)diformyl-4-chloro-phenolate) nickel(II) adapts an ideal parallelogram, in which the Ni atom is coordinated with two phenolic oxygen atoms [O(1), O(1A)] and two imino nitrogen atoms [N(1), N(1A)].     

Single-crystal structure determination of a new polymorph (ε-Alq<Subscript>3</Subscript>) of the electroluminescence OLED (organic light-emitting diode) material,tris(8-hydroxyquinoline)aluminum (Alq<Subscript>3</Subscript>)

Tris(8-hydroxyquinoline) aluminum, Alq₃, is the most widely used electroluminescent material in organic light-emitting diode (OLED), chemistry. Single-crystal structure determination of a new polymorph of Alq₃, designated as -Alq₃, is described. There are three molecules of Alq₃ in the asymmetric unit. This octahedrally coordinated complex crystallizes in the triclinic space group P-1, lattice parameters a = 13.5190(5) Å, b = 15.8550(6)~Å, c = 18.7110(8) Å, = 95.4940(19), = 109.774(2), = 114.6270(16), Volume = 3296.8(2) ų, Z = 6, Z = 3.     

Crystal structures of five policyclic compounds related to the natural product forskolin

(3(Z),4,6a,9a,9b)-(±)-3a,4,6a,7,8,9,9a,9b-octahydro-4,7,7, 9b-tetramethyl-3a-[3-(methoxymethyloxy)-3-methyl-1-butenyl]-5H-naphto[1,8-de]-1,3-dioxin-6-one (I), C₂₂H₃₆O₅,M _r=378.51, monoclinic,P2₁/n,a=6.330(1),b=14.576(2),c=22.837(2)Å,=93.04(1)°,V=2104.1(2)ų,Z=4,D _c=1.19 Mg/m³, (MoK)=0.71069Å,=0.8 cm^–1,F(000)=832,T=298 K,R=0.054 for 1971 observed reflections; (7a,10a,10b,12)-(±)-7a,9, 10,10a,10b,11,12,12a-octahydro-2,2,10,10,10b,12a-hexamethyl-2H,8H-1-benzopyrano[4a,5,6,-de][1,3,2]-benzodioxin-11-one (II), C₂₀H₂₉O₄,M _r=334.5, triclinic,P-1,a=10.595(2),b=12.152(1),c=8.073(1)Å,=106.53(1),=105.65(1), =66.29(1)°,V=897.9(2)ų,Z=2,D _c=1.24 Mg/m³, (MoK)=0.71069Å,=0.8 cm^–1,F(000)=362,T=298 K,R=0.046 for 2848 observed reflections; (7a,10a,10b,12, 12a)-(±)-7a,9,10,10a,10b,11,12,12a-octahydro-2,2,10,10,10b,12a-hexamethyl-2H,8H-1-benzopyrano[4a,5,6-de][1,3,2]-benzodioxin-11, 12-diol (III), C₂₀H₃₂O₅ (two molecules in the asymmetric unit),M _r=352.2, triclinic,P-1,a=12.948(3),b=13.615(3),c=12.197(4)Å,=101.16(2),=111.88(2), =69.48(2)°,V=1863.8(9)ų,Z=2,D _C=1.26 Mg/m³,(MoK)=0.71069 Å,=0.8 cm^–1,F(000)=768,T=298 K,R=0.060 for 4570 observed reflections; 4-acetoxy-4-[[(4a,5,8a)-(±)-hexahydro-4a,6,6-trimethyl-4H-1,3-benzodioxin-4-one]-5-yl]butan-2-one (IV), C₁₇H₂₆O₆,M _r=326.4, monoclinic,P2₁/c,a=10.495(2),b=12.050(2),c=14.216(2)Å,=108.51(1)°,V=1704.8(5)ų,Z=4,D _c=1.27 Mg/m³,(MoK)=0.71069 Å,=0.9 cm^–1,F(000)=704,T=298 K,R=0.049 for2455 observed reflections; (3a,4,5,6,6a,9a,9b)-(±)-4,5-epoxy-decahydro-3, 3a-dihydroxy-2-ethoxy-4,7,7,9b-tetramethyl-naphto-[1,8-bc]-pyran-6-ol-acetate (V), C₂₀H₃₂O₇,M _r=383.5, monoclinic,C2/c,a=10.353(2),b=17.975(3),c=21.188(3)Å,=91.29(1)°,V=3942(1)ų,Z=8,D _c=1.29 Mg/m³,(MoK)=0.71069 Å,=0.8 cm^–1,F(000)=1664,T=298 K,R=0.051 for 2120 observed reflections. We report here the complete structures of four decalin derivatives (compoundsI, II, III, V) and one related compound (compoundIV) synthetized in order to find an efficient synthetic approach for the natural productforskolin.