Water‐mediated intermolecular interactions in 1,2‐O‐cyclohexylidene‐myo‐inositol: a quantitative analysis

The syntheses of new myo‐inositol derivatives have received much attention due to their important biological activities. 1,2‐O‐Cyclohexylidene‐myo‐inositol is an important intermediate formed during the syntheses of certain myo‐inositol derivatives. We report herein the crystal structure of 1,2‐O‐cyclohexylidene‐myo‐inositol dihydrate, C₁₂H₂₀O₆·2H₂O, which is an intermediate formed during the syntheses of myo‐inositol phosphate derivatives, to demonstrate the participation of water molecules and hydroxy groups in the formation of several intermolecular O—H…O interactions, and to determine a low‐energy conformation. The title myo‐inositol derivative crystallizes with two water molecules in the asymmetric unit in the space group C 2/c , with Z = 8. The water molecules facilitate the formation of an extensive O—H…O hydrogen‐bonding network that assists in the formation of a dense crystal packing. Furthermore, geometrical optimization and frequency analysis was carried out using density functional theory (DFT) calculations with B3LYP hybrid functionals and 6‐31G(d), 6‐31G(d,p) and 6‐311G(d,p) basis sets. The theoretical and experimental structures were found to be very similar, with only slight deviations. The intermolecular interactions were quantitatively analysed using Hirshfeld surface analysis and 2D (two‐dimensional) fingerplot plots, and the total lattice energy was calculated.     

Five 2‐aryl‐substituted tetrahydro‐1,4‐epoxy‐1‐benzazepines: isolated molecules and hydrogen‐bonded chains and sheets

(2SR,4RS)‐2‐exo‐Phenyl‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₆H₁₅NO, (I), (2SR,4RS)‐2‐exo‐(4‐chlorophenyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₆H₁₄ClNO, (II), and (2SR,4RS)‐2‐exo‐(3‐methylphenyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₇H₁₇NO, (III), all crystallize with Z′ = 2, in the space groups Cc, P2₁/n and P2₁/c, respectively. In each of (II) and (III), the conformations of the two independent molecules are significantly different. The molecules in (I) are linked by C—H...π(arene) hydrogen bonds to form two independent chains, each containing only one type of molecule. The molecules in (II) are linked into sheets by a combination of C—H...O, C—H...(N,O) and C—H...π(arene) hydrogen bonds, all of which link pairs of molecules related by inversion, while in (III), the molecules are linked into sheets by a combination of C—H...N, C—H...O and C—H...π(arene) hydrogen bonds. There are no direction‐specific intermolecular interactions of any kind in the structure of (2SR,4RS)‐7‐bromo‐2‐exo‐phenyl‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₆H₁₄BrNO, (IV), but in the structure of (2SR,4RS)‐2‐exo‐(4‐bromophenyl)‐7‐chloro‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₆H₁₃BrClNO, (V), a combination of one C—H...N hydrogen bond and one C—H...O hydrogen bond links the molecules into sheets of alternating centrosymmetric R²₂(14) and R⁶₆(22) rings. Comparisons are made with the structures of a number of related compounds.     

Two methyl 3‐(1H‐pyrazol‐4‐yl)octahydropyrrolo[3,4‐c]pyrrole‐1‐carboxylates form different hydrogen‐bonded sheets

In the molecules of both methyl (1RS,3SR,3aRS,6aSR)‐1‐methyl‐3‐(3‐methyl‐1‐phenyl‐1H‐pyrazol‐4‐yl)‐4,6‐dioxo‐5‐phenyloctahydropyrrolo[3,4‐c]pyrrole‐1‐carboxylate, C₂₅H₂₄N₄O₄, (I), and methyl (1RS,3SR,3aRS,6aSR)‐5‐(4‐chlorophenyl)‐1‐methyl‐3‐(3‐methyl‐1‐phenyl‐1H‐pyrazol‐4‐yl)‐4,6‐dioxooctahydropyrrolo[3,4‐c]pyrrole‐1‐carboxylate, C₂₅H₂₃ClN₄O₄, (II), the two rings of the pyrrolopyrrole fragment are both nonplanar, with conformations close to half‐chair forms. The overall conformations of the molecules of (I) and (II) are very similar, apart from the orientation of the ester function. The molecules of (I) are linked into sheets by a combination of an N—H...π(pyrrole) hydrogen bond and three independent C—H...O hydrogen bonds. The molecules of (II) are also linked into sheets, which are generated by a combination of an N—H...N hydrogen bond and two independent C—H...O hydrogen bonds, weakly augmented by a C—H...π(arene) hydrogen bond.     

(–)‐epi‐Inosose‐2

The structure of the title compound, C₆H₁₀O₆, was determined to confirm the position of the keto group in the mol­ecule prepared enantioselectively by a bioconversion from myo‐inositol. There are two independent mol­ecules showing similar geometry.     

Three styryl‐substituted tetrahydro‐1,4‐epoxy‐1‐benzazepines: configurations,conformations and hydrogen‐bonded chains

(2SR,4RS)‐7‐Chloro‐2‐exo‐[(E)‐styryl]‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₈H₁₆ClNO, (I), crystallizes as a racemic twin in the space group P2₁ and the molecules are linked into a chain of edge‐fused R₃³(9) rings by a combination of C—H...O and C—H...N hydrogen bonds. The diastereoisomer (2RS,4RS)‐7‐chloro‐2‐endo‐[(E)‐styryl]‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, (II), also crystallizes as a racemic twin, but in the space group P2₁2₁2₁, and a two‐centre C—H...N hydrogen bond and a three‐centre C—H...(O,N) hydrogen bond combine to link the molecules into a complex chain of rings. In (2R,4R)‐7‐fluoro‐2‐endo‐[(E)‐styryl]‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₈H₁₆FNO, (III), which is not isomorphous with (II), the molecules are linked by a single C—H...O hydrogen bond into simple chains, but the molecular arrangements in (II) and (III) are nonetheless very similar. The significance of this study lies in its observation of the variations in molecular configuration and conformation, and in the variation in the supramolecular aggregation, consequent upon modest changes in the peripheral substituents.     

Relative configuration,absolute configuration and absolute structure of three isomeric 8‐benzyl‐2‐[(4‐bromophenyl)(hydroxy)methyl]‐8‐azabicyclo[3.2.1]octan‐3‐ones

The title compounds, C₂₁H₂₂BrNO₂, are isomeric 8‐benzyl‐2‐[(4‐bromophenyl)(hydroxy)methyl]‐8‐azabicyclo[3.2.1]octan‐3‐ones. Compound (I), the (±)‐exo,syn‐(1RS,2SR,5SR,9SR) isomer, crystallizes in the hexagonal space group R, while compounds (II) [the (+)‐exo,anti‐(1R,2S,5S,9R) isomer] and (III) [the (±)‐exo,anti‐(1RS,2SR,5SR,9RS) isomer] crystallize in the orthorhombic space groups P2₁2₁2₁ and Pna2₁, respectively. The absolute configuration was determined for enantiomerically pure (II). For the noncentrosymmetric crystal of (III), its absolute structure was established. In the crystal structures of (I) and (II), an intramolecular hydrogen bond is formed between the hydroxy group and the heterocyclic N atom. In the crystal structure of racemic (III), hydrogen‐bonded chains of molecules are formed via intermolecular O—H...O interactions. Additionally, face‐to‐edge π–π interactions are present in the crystal structures of (I) and (II). In all three structures, the piperidinone rings adopt chair conformations and the N‐benzyl substituents occupy the equatorial positions.     

Dipolar S=O...C=O and C—H...O interactions in the molecular organization of 4,6‐di‐O‐acetyl‐2‐O‐tosyl‐myo‐inositol 1,3,5‐orthoesters

In the absence of conventional hydrogen bonding, the molecules of 4,6‐di‐O‐acetyl‐2‐O‐tosyl‐myo‐inositol 1,3,5‐orthoformate, C₁₈H₂₀O₁₀S, (I), and 4,6‐di‐O‐acetyl‐2‐O‐tosyl‐myo‐inositol 1,3,5‐orthobenzoate, C₂₄H₂₄O₁₀S, (II), are associated via C—H...O interactions. Molecules of (II) are additionally linked via dipolar S=O...C=O contacts. It is interesting to note that the sulfonyl O atom involved in the dipolar S=O...C=O contacts does not take part in any other interaction, indicating the competitive nature of this contact relative to the weak hydrogen‐bonding interactions.     

Three tetrahydro‐1,4‐epoxy‐1‐benzazepines carrying pendent heterocyclic substituents: supramolecular structures in zero,one or two dimensions

(2SR,4RS)‐7‐Fluoro‐2‐exo‐(2‐furyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₄H₁₂FNO₂, (I), crystallizes with Z′ = 2 in the space group P2₁/c. A combination of three C—H...O hydrogen bonds and one C—H...N hydrogen bond links the molecules into a complex chain of rings, and pairs of such chains are linked into a tube‐like structure by two C—H...π(arene) hydrogen bonds. There are no hydrogen bonds in the structure of racemic (2SR,4RS)‐2‐exo‐(5‐bromo‐2‐thienyl)‐7‐fluoro‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₄H₁₁BrFNOS, (II), while the molecules of (2S,4R)‐2‐exo‐(5‐bromo‐2‐thienyl)‐7‐trifluoromethoxy‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₅H₁₄BrF₃NO₂S, (III), are linked into sheets by a combination of two C—H...O hydrogen bonds and one C—H...π(arene) hydrogen bond. The significance of this study lies in its observation of the wide variation in the patterns of supramolecular aggregation, consequent upon modest changes in the peripheral substituents.     

Enhancing Intermolecular Benzoyl‐Transfer Reactivity in Crystals by Growing a “Reactive” Metastable Polymorph by Using a Chiral Additive

Racemic 2,4‐di‐O‐benzoyl‐myo‐inositol‐1,3,5‐orthoacetate, which normally crystallizes in a monoclinic form (form I, space group P2₁/n) could be persuaded to crystallize out as a metastable polymorph (form II, space group C2/c) by using a small amount of either D ‐ or L ‐ 2,4‐di‐O‐benzoyl‐myo‐inositol‐1,3,5‐orthoformate as an additive in the crystallization medium. The structurally similar enantiomeric additive was chosen by the scrutiny of previous experimental results on the crystallization of racemic 2,4‐di‐O‐benzoyl‐myo‐inositol‐1,3,5‐orthoacetate. Form II crystals can be thermally transformed to form I crystals at about 145 °C. The relative organization of the molecules in these dimorphs vary slightly in terms of the helical assembly of molecules, that is, electrophile (El)???nucleophile (Nu) and C? H???π interactions, but these minor variations have a profound effect on the facility and specificity of benzoyl‐group‐transfer reactivity in the two crystal forms. While form II crystals undergo a clean intermolecular benzoyl‐group‐transfer reaction, form I crystals are less reactive and undergo non‐specific benzoyl‐group transfer leading to a mixture of products. The role played by the additive in fine‐tuning small changes that are required in the molecular packing opens up the possibility of creating new polymorphs that show varied physical and chemical properties. Crystals of D ‐2,6‐di‐O‐benzoyl‐myo‐inositol‐1,3,5‐orthoformate (additive) did not show facile benzoyl‐group‐transfer reactivity (in contrast to the corresponding racemic compound) due to the lack of proper juxtaposition and assembly of molecules.     

Correlation of the solid‐state reactivities of racemic 2,4(6)‐di‐O‐benzoyl‐myo‐inositol 1,3,5‐orthoformate and its 4,4′‐bipyridine cocrystal with their crystal structures

Racemic 2,4(6)‐di‐O‐benzoyl‐myo‐inositol 1,3,5‐orthoformate, C₂₁H₁₈O₈, (1) , shows a very efficient intermolecular benzoyl‐group migration reaction in its crystals. However, the presence of 4,4′‐bipyridine molecules in its cocrystal, C₂₁H₁₈O₈·C₁₀H₈N₂, (1)·BP , inhibits the intermolecular benzoyl‐group transfer reaction. In (1) , molecules are assembled around the crystallographic twofold screw axis (b axis) to form a helical self‐assembly through conventional O—H...O hydrogen‐bonding interactions. This helical association places the reactive C6‐O‐benzoyl group (electrophile, El) and the C4‐hydroxy group (nucleophile, Nu) in proximity, with a preorganized El...Nu geometry favourable for the acyl transfer reaction. In the cocrystal (1)·BP , the dibenzoate and bipyridine molecules are arranged alternately through O—H...N interactions. The presence of the bipyridine molecules perturbs the regular helical assembly of the dibenzoate molecules and thus restricts the solid‐state reactivity. Hence, unlike the parent dibenzoate crystals, the cocrystals do not exhibit benzoyl‐transfer reactions. This approach is useful for increasing the stability of small molecules in the crystalline state and could find application in the design of functional solids.     

Different hydrogen‐bonded structures in three 2‐thienyl‐substituted tetrahydro‐1,4‐epoxy‐1‐benzazepines

The molecules of (2RS,4SR)‐2‐exo‐(5‐bromo‐2‐thienyl)‐7‐chloro‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₄H₁₁BrClNOS, (I), are linked into cyclic centrosymmetric dimers by C—H...π(thienyl) hydrogen bonds. Each such dimer makes rather short Br...Br contacts with two other dimers. In (2RS,4SR)‐2‐exo‐(5‐methyl‐2‐thienyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₅H₁₅NOS, (II), a combination of C—H...O and C—H...π(thienyl) hydrogen bonds links the molecules into chains of rings. A more complex chain of rings is formed in (2RS,4SR)‐7‐chloro‐2‐exo‐(5‐methyl‐2‐thienyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₅H₁₄ClNOS, (III), built from a combination of two independent C—H...O hydrogen bonds, one C—H...π(arene) hydrogen bond and one C—H...π(thienyl) hydrogen bond.     

Three closely related thienyl‐substituted 1,4‐epoxynaphtho[1,2‐b]azepines: hydrogen‐bonded assembly in one,two and three dimensions

(2R,4S)‐2‐(3‐Methylthiophen‐2‐yl)‐2,3,4,5‐tetrahydro‐1,4‐epoxynaphtho[1,2‐b]azepine, C₁₉H₁₇NOS, (I), crystallizes with a single enantiomer in each crystal, whereas its geometrical isomer (2RS,4SR)‐2‐(5‐methylthiophen‐2‐yl)‐2,3,4,5‐tetrahydro‐1,4‐epoxy‐naphtho[1,2‐b]azepine, (II), and (2RS,4SR)‐2‐(5‐bromothiophen‐2‐yl)‐2,3,4,5‐tetrahydro‐1,4‐epoxynaphtho[1,2‐b]azepine, C₁₈H₁₄BrNOS, (III), both crystallize as racemic mixtures. A combination of one C—H...O hydrogen bond and two C—H...π(arene) hydrogen bonds links the molecules of (I) into a three‐dimensional framework; the molecules of (II) are linked into a C(4)C(4)[R₂²(7)] chain of rings by a combination of C—H...N and C—H...O hydrogen bonds; and in (III), where Z′ = 2, a combination of four C—H...π(arene) hydrogen bonds and two C—H...π(thienyl) hydrogen bonds links the molecules into complex sheets. Comparisons are made with the assembly patterns in some aryl‐substituted 1,4‐epoxynaphtho[1,2‐b]azepines.     

Hydrogen‐bonding patterns in 3‐alkyl‐3‐hydroxyindolin‐2‐ones

The molecules of racemic 3‐benzoylmethyl‐3‐hydroxyindolin‐2‐one, C₁₆H₁₃NO₃, (I), are linked by a combination of N—H...O and O—H...O hydrogen bonds into a chain of centrosymmetric edge‐fused R₂²(10) and R₄⁴(12) rings. Five monosubstituted analogues of (I), namely racemic 3‐hydroxy‐3‐[(4‐methylbenzoyl)methyl]indolin‐2‐one, C₁₇H₁₅NO₃, (II), racemic 3‐[(4‐fluorobenzoyl)methyl]‐3‐hydroxyindolin‐2‐one, C₁₆H₁₂FNO₃, (III), racemic 3‐[(4‐chlorobenzoyl)methyl]‐3‐hydroxyindolin‐2‐one, C₁₆H₁₂ClNO₃, (IV), racemic 3‐[(4‐bromobenzoyl)methyl]‐3‐hydroxyindolin‐2‐one, C₁₆H₁₂BrNO₃, (V), and racemic 3‐hydroxy‐3‐[(4‐nitrobenzoyl)methyl]indolin‐2‐one, C₁₆H₁₂N₂O₅, (VI), are isomorphous in space group P. In each of compounds (II)–(VI), a combination of N—H...O and O—H...O hydrogen bonds generates a chain of centrosymmetric edge‐fused R₂²(8) and R₂²(10) rings, and these chains are linked into sheets by an aromatic π–π stacking interaction. No two of the structures of (II)–(VI) exhibit the same combination of weak hydrogen bonds of C—H...O and C—H...π(arene) types. The molecules of racemic 3‐hydroxy‐3‐(2‐thienylcarbonylmethyl)indolin‐2‐one, C₁₄H₁₁NO₃S, (VII), form hydrogen‐bonded chains very similar to those in (II)–(VI), but here the sheet formation depends upon a weak π–π stacking interaction between thienyl rings. Comparisons are drawn between the crystal structures of compounds (I)–(VII) and those of some recently reported analogues having no aromatic group in the side chain.     

Four differently substituted 2‐aryl‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepines: hydrogen‐bonded structures in one,two and three dimensions

In (2RS,4SR)‐7‐chloro‐2‐exo‐(2‐chloro‐6‐fluorophenyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₆H₁₂Cl₂FNO, (I), molecules are linked into chains by a single C—H...π(arene) hydrogen bond. (2RS,4SR)‐2‐exo‐(2‐Chloro‐6‐fluorophenyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₆H₁₃ClFNO, (II), is isomorphous with compound (I) but not strictly isostructural with it, as the hydrogen‐bonded chains in (II) are linked into sheets by an aromatic π–π stacking interaction. The molecules of (2RS,4SR)‐7‐methyl‐2‐exo‐(4‐methylphenyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₈H₁₉NO, (III), are linked into sheets by a combination of C—H...N and C—H...π(arene) hydrogen bonds. (2S,4R)‐2‐exo‐(2‐Chlorophenyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₁₆H₁₄ClNO, (IV), crystallizes as a single enantiomer and the molecules are linked into a three‐dimensional framework structure by a combination of one C—H...O hydrogen bond and three C—H...π(arene) hydrogen bonds.     

Facile Synthesis of 7‐epi‐Taxane and Its Derivatives and Preliminary Evaluation of Anticancer Activity

7‐epi‐Taxane has been achieved efficiently in gram scale from natural taxane via inversion of the 7‐hydroxyl group simply using Ag₂O as catalyst and DMF as solvent. The catalyst could be quantitatively recovered by filtration without loss of catalytic activity. This condition is also applicable to the direct epimerization of taxane derivatives (e.g., docetaxel and paclitaxel) to 7‐epi‐taxane derivatives (e.g., 7‐epi‐docetaxel and 7‐epi‐paclitaxel). Furthermore, 33 ester derivatives of 7‐epi‐taxane with different amino acid moieties at the position of C‐13 were successfully synthesized via esterification without protecting C‐7‐OH. Bioassay results revealed that compounds 13 and 18 have good selectivity against prostatic cancer cell line DU145, with IC₅₀ value as low as 15.9 nmol/L for 18 .     

Chiral crystals from an achiral molecule: 4,6‐di‐O‐benzyl‐1,3‐O‐benzylidene‐2‐O‐(4‐methoxybenzyl)‐myo‐5‐inosose

The title achiral compound, C₃₅H₃₄O₇, crystallizes in the chiral monoclinic space group P2₁. The molecules are densely packed to form a helical assembly along the crystallographic twofold screw axis via C—H...O and C—H...π interactions. Interestingly, the unit‐translated helical chains are loosely connected via a rather uncommon edge‐to‐edge Ph—H...H—Ph short contact (H...H = 2.33 Å).     

Regio‐ and stereospecific assembly of dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidines] from simple precursors using a one‐pot procedure: synthesis,spectroscopic and structural characterization,and a proposed mechanism of formation

The synthesis and characterization of three new dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine] compounds are reported, together with the crystal structures of two of them. (3RS,1′SR,2′SR,7a′SR)‐2′‐(4‐Chlorophenyl)‐1‐hexyl‐2′′‐sulfanylidene‐5′,6′,7′,7a′‐tetrahydro‐2′H‐dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine]‐2,4′′‐dione, C₂₈H₃₀ClN₃O₂S₂, (I), (3RS,1′SR,2′SR,7a′SR)‐2′‐(4‐chlorophenyl)‐1‐benzyl‐5‐methyl‐2′′‐sulfanylidene‐5′,6′,7′,7a′‐tetrahydro‐2′H‐dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine]‐2,4′′‐dione, C₃₀H₂₆ClN₃O₂S₂, (II), and (3RS,1′SR,2′SR,7a′SR)‐2′‐(4‐chlorophenyl)‐5‐fluoro‐2′′‐sulfanylidene‐5′,6′,7′,7a′‐tetrahydro‐2′H‐dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine]‐2,4′′‐dione, C₂₂H₁₇ClFN₃O₂S₂, (III), were each isolated as a single regioisomer using a one‐pot reaction involving l ‐proline, a substituted isatin and (Z)‐5‐(4‐chlorobenzylidene)‐2‐sulfanylidenethiazolidin‐4‐one [5‐(4‐chlorobenzylidene)rhodanine]. The compositions of (I)–(III) were established by elemental analysis, complemented by high‐resolution mass spectrometry in the case of (I); their constitutions, including the definition of the regiochemistry, were established using NMR spectroscopy, and the relative configurations at the four stereogenic centres were established using single‐crystal X‐ray structure analysis. A possible reaction mechanism for the formation of (I)–(III) is proposed, based on the detailed stereochemistry. The molecules of (I) are linked into simple chains by a single N—H…N hydrogen bond, those of (II) are linked into a chain of rings by a combination of N—H…O and C—H…S=C hydrogen bonds, and those of (III) are linked into sheets by a combination of N—H…N and N—H…S=C hydrogen bonds.     

Four 1‐naphthyl‐substituted tetrahydro‐1,4‐epoxy‐1‐benzazepines: hydrogen‐bonded structures in one,two and three dimensions

(2S*,4R*)‐2‐exo‐(1‐Naphthyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₂₀H₁₇NO, (I), crystallizes with Z′ = 2 in the space group P2₁; the two independent molecules have the same absolute configuration, although this configuration is indeterminate. The molecules of each type are linked by a combination of C—H...O and C—H...π(arene) hydrogen bonds to form two independent sheets, each containing only one type of molecule. (2SR,4RS)‐7‐Methyl‐2‐exo‐(1‐naphthyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₂₁H₁₉NO, (II), crystallizes as a true racemate in the space group P2₁/c, and a combination of C—H...N, C—H...O and C—H...π(arene) hydrogen bonds links the molecules into sheets, each containing equal numbers of the two enantiomorphs. (2S*,4R*)‐2‐exo‐(1‐Naphthyl)‐7‐trifluoromethyl‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₂₁H₁₆F₃NO₂, (III), crystallizes as a single enantiomorph, as for (I), but now with Z′ = 1 in the space group P2₁2₁2₁; again, the absolute configuration is indeterminate. A single C—H...π(arene) hydrogen bond links the molecules of (III) into simple chains. (2S,4R)‐8‐Chloro‐9‐methyl‐2‐exo‐(1‐naphthyl)‐2,3,4,5‐tetrahydro‐1H‐1,4‐epoxy‐1‐benzazepine, C₂₁H₁₈ClNO, (IV), crystallizes as a single enantiomorph of well defined configuration, in the space group P2₁2₁2₁, where two independent C—H...π(arene) hydrogen bonds link the molecules into a single three‐dimensional framework structure.     

Different interaction motifs of dipolar S=O...C=O contacts that associate diastereomers of 2,4(6)‐di‐O‐benzoyl‐6(4)‐O‐{[(1S)‐7,7‐dimethyl‐2‐oxobicyclo[2.2.1]heptan‐1‐ylmethyl]sulfonyl}‐myo‐inositol 1,3,5‐orthoacetate

Diastereomeric mixtures of 2,4(6)‐di‐O‐benzoyl‐6(4)‐O‐[(1S)‐10‐camphorsulfonyl]‐myo‐inositol 1,3,5‐orthoesters associate in their crystal structures via different geometries of S=O...C=O short contacts, depending upon the substitution. A comparison of the dimeric association in the orthoacetate and orthoformate (solvated) derivatives shows a sheared parallel motif of dipolar S=O...C=O contacts bridging the former, whereas perpendicular S=O...C=O contacts occur in the latter. The title compound, C₃₂H₃₄O₁₁S, is chiral, owing to the presence of the camphor moiety.