Precursor of a β‐lactamase inhibitor: allyl (4S,8S,9R)‐10‐[(E)‐ethyl­idene]‐4‐methoxy‐11‐oxo‐1‐aza­tri­cyclo­[7.2.0.03,8]­undec‐2‐ene‐2‐carboxyl­ate

The molecular structure of the title tricyclic compound, C₁₇H₂₁NO₄, which is the immediate precursor of a potent synthetic inhibitor {Lek157: sodium (8S,9R)‐10‐[(E)‐ethyl­idene]‐4‐methoxy‐11‐oxo‐1‐aza­tri­cyclo­[7.2.0.0^3,8]­undec‐2‐ene‐2‐carboxyl­ate} with remarkable potency, provides experimental evidence for the previously modelled relative position of the fused cyclo­hexyl ring and the carbonyl group of the β‐lactam ring, which takes part in the formation of the initial tetrahedral acyl–enzyme complex. In this hydro­phobic mol­ecule, the overall geometry is influenced by C—H?O intramolecular hydrogen bonds [3.046 (4) and 3.538 (6) Å, with corresponding normalized H?O distances of 2.30 and 2.46 Å], whereas the mol­ecules are interconnected through intermolecular C—H?O hydrogen bonds [3.335 (4)–3.575 (5) Å].     

(1R,8R,11R)‐3,3,11‐Tri­methyl‐6,6‐ethyl­ene­dioxy­bi­cyclo­[6.3.0]­undecan‐2‐one and (1R,2R,8R,11R)‐3,3,11‐tri­methyl‐6,6‐ethylenedioxybicyclo[6.3.0]undecan‐2‐ol

The reduction of (1R,8R,11R)‐3,3,11‐tri­methyl‐6,6‐ethyl­ene­dioxy­bi­cyclo­[6.3.0]­undecan‐2‐one, C₁₆H₂₆O₃, (I), gave exclusively an alcohol, C₁₆H₂₈O₃, (II). The stereochemistry of the hydroxyl group in (II) was shown as R. The conformation around the eight‐membered carbocycle in (I) differs markedly from that in (II).     

Chiral and meso‐bis([2.2]­para­cyclo­phan‐4‐yl)­methane and meso‐bis­([2.2]­para­cyclo­phan‐4‐yl) sulfide

The [2.2]­para­cyclo­phane groups of the title compounds, chiral and meso‐bis­(tri­cyclo­[8.2.2.2^4,7]­hexa­deca‐4,6,10,12,13,15‐hexa­en‐5‐yl)­methane (the former as a racemate), C₃₃H₃₂, and meso‐bis­(tri­cyclo­[8.2.2.2^4,7]­hexa­deca‐4,6,10,12,13,15‐hexa­en‐5‐yl) sulfide, C₃₂H₃₀S, show the characteristic structural features of the parent compound [2.2]­para­cyclo­phane and the related compound di­methylbis([2.2]­para­cyclo­phan‐4‐yl)­silane, C₃₄­H₃₆­Si: the aromatic rings are puckered, resulting in a boat conformation. The planes of the four coplanar C atoms are slightly twisted with respect to each other. The Csp³—Csp³ bond lengths of the ethyl­ene bridges are elongated by the electronic and steric effects of the skeleton.     

Bis(1‐phenyl­ethyl­ammonium) hexa­chloridostannate(IV) and bis­(2‐phenyl­ethyl­ammonium) hexa­chloridostannate(IV)

The crystal structures of the two isomers bis­(1‐phenyl­ethyl­ammonium) hexa­chloridostannate(IV) and bis­(2‐phenyl­ethyl­ammonium) hexa­chloridostannate(IV), both (C₈H₁₂N)₂[SnCl₆], exhibit alternating organic and inorganic layers, which inter­act via N—H⋯Cl hydrogen bonding. The inorganic layer contains an extended two‐dimensional hydrogen‐bonded sheet. The Sn atom in the 1‐phenylethyl­ammonium salt lies on an inversion centre.     

Two isomers of 2,4‐di­benzyl‐8‐azabicyclo­[3.2.1]­octan‐3‐ol

The crystal structures of the title compounds, 2α,4α‐di­benzyl‐3α‐tropanol (2α,4α‐di­benzyl‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octan‐3α‐ol), C₂₂H₂₇NO, (I), and 2α,4α‐di­benzyl‐3β‐tropanol (2α,4α‐di­benzyl‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octan‐3β‐ol), C₂₂H₂₇NO, (II), show that both compounds have a piperidine ring in a chair conformation and a pyrrolidine ring in an envelope conformation. Isomer (I) is asymmetric, the benzyl groups having different orientations, whereas isomer (II) is mirror symmetric, and the N and O atoms, the C atom attached to the hydroxy group, and the methyl C atom attached to the N atom lie on the mirror plane. In the crystal structures of both (I) and (II), the mol­ecules are linked together by intermolecular O—H⋯N hydrogen bonds to form chains that run parallel to the a direction in (I) and parallel to b in (II).     

The layered structure of poly­[[di‐μ‐chloro‐bis­[chloro(2‐ethyl­tetrazole‐κN4)copper(II)]]‐di‐μ‐2‐ethyl­tetrazole‐κ2N1:N4]

In the polymeric title complex, [CuCl₂(C₃H₆N₄)₂]_n, there are two ligands in the asymmetric unit. The Cu atom adopts an elongated octahedral geometry, with two 2‐ethyl­tetrazole ligands [Cu—N = 2.0037 (16) and 2.0136 (16) Å] and two Cl atoms [Cu—Cl = 2.2595 (6) and 2.2796 (6) Å] in equatorial positions. A Cl atom and a symmetry‐related 2‐ethyl­tetrazole mol­ecule [Cu—Cl = 2.8845 (8) Å and Cu—N = 2.851 (2) Å] lie in the axial positions of the octahedron. One of the two 2‐­ethyltetrazole ligands of the asymmetric unit exhibits bidentate binding to two Cu atoms through two N atoms of the tetrazole ring, whereas the other ligand is coordinated in a monodentate fashion via one tetrazole N atom. The Cu‐atom octahedra form dimer entities by sharing edges with equatorial and axial Cl atoms. The dimers are linked together through the 2‐ethyl­tetrazole ligands to form one‐dimensional polymeric zigzag chains extending along the b axis. The chains are connected into infinite layers parallel to the (10) plane via the 2‐ethyl­tetrazole ligands.     

5‐Cyano­tropolone and 5‐nitro­tropolone

The title compounds, 4‐hydroxy‐5‐oxo‐1,3,6‐cyclo­heptatriene‐1‐carbo­nitrile, C₈H₅NO₂, (I), and 2‐hydroxy‐5‐nitro‐2,4,6‐cyclo­heptatrien‐1‐one, C₇H₅NO₄, (II), have intra‐ and intermolecular hydrogen bonds. The structure of (II) contains two crystallographically independent mol­ecules, (IIa) and (IIb). An intermolecular π–π interaction and an intermolecular NO₂?π–π interaction are present in (I) and (II), respectively.     

1,3‐Propane­di­ammonium bis(3′‐nitro‐trans‐cinnamate) and trans‐1,2‐cyclo­hexane­di­ammonium bis(3′‐nitro‐trans‐cinnamate)

In the title two adducts, C₃H₁₂N₂²⁺·2C₉H₆NO₄^?, (I), and C₆H₁₆N₂²⁺·2C₉H₆NO₄^?, (II), hydrogen bonds between the di­ammonium and carboxyl­ate ions form a two‐dimensional network parallel to the ab plane in (I) and one‐dimensional chains along the c axis in (II). The cyclo­hexane­di­ammonium ion in (II) has a crystallographic twofold axis.     

Two 2,2‐dihalo‐N‐(1‐phenyl­ethyl)­cyclo­propane‐1‐carbox­amides

The crystal structures of (1R,1′S)‐2′,2′‐di­chloro‐N‐(1‐phenyl­ethyl)­cyclo­propane‐1′‐carbox­amide, C₁₂H₁₃Cl₂NO, (I), and (1R,1′R)‐2′,2′‐di­fluoro‐N‐(1‐phenyl­ethyl)­cyclo­propane‐1′‐car­box­amide, C₁₂H₁₃F₂NO, (II), have been determined. Both crystals contain two independent mol­ecules with different conformations of the phenyl­ethyl groups. In the crystals of both compounds, the mol­ecules are linked together by N—H⃛O hydrogen bonds, thus forming chains in the a direction.     

Hexa‐μ2‐chloro‐μ4‐oxo‐tetrakis[(2‐ethyl­tetrazole‐κN4)copper(II)]

In the title molecular complex, [Cu₄Cl₆O(2‐EtTz)₄], where 2‐EtTz is 2‐ethyl­tetrazole (C₃H₆N₄), the central O atom is located on the symmetry site and is tetrahedrally coordinated to four Cu atoms, with Cu—O distances of 1.8966 (4) Å. A very slight distortion of Cu₄O from a regular tetrahedron is observed [two Cu—O—Cu angles are 108.76 (3)° and four others are 109.828 (13)°]. Each Cu atom is connected to three others via the Cl atoms, forming a slightly distorted Cl octahedron around the O atom, with O⋯Cl distances of 2.9265 (7) Å for Cl atoms lying on the twofold axis and 2.9441 (13) Å for those in general positions. The Cu atom has a distorted trigonal–bipyramidal environment, with three Cl atoms in the equatorial plane, and with the N atom of the 2‐ethyl­tetrazole ligand and the μ₄‐O atom in axial positions. The Cu atom is displaced out of the equatorial plane by ca 0.91 Å towards the coordinated N atom of the 2‐­ethyl­tetrazole ligand.     

A `tetrameric' 3,4‐di‐p‐tolyl‐1,2,5‐oxadiborole derivative

In the title compound, 1,1,6a,7,9a,10‐hexa­chloro‐2,3,5,6,8,9,11,12‐octa‐p‐tolyl‐1,6a,9a,12a‐tetraborata‐3a,4a,7,10‐tetrabora‐4a¹,6b,9b,12b‐tetraoxonia‐4‐oxatetra­cyclo­penta­[1,2‐a:2,1,5‐de:1,2‐g:1,2‐i]­naphthalene di­chloro­methane pentasolvate, C₆₄H₅₆B₈Cl₆O₅·5CH₂Cl₂, two condensed oxadiborole rings are attached to two further oxadiborole rings in a type of donor–acceptor bonding, thus forming a ten‐membered alternating (B—O)₅ naphthalene‐like arrangement as the central building block.     

catena‐Poly[[{4‐bromo‐2‐[2‐(di­methyl­amino)­ethyl­imino­meth­yl]­phenolato}­copper(II)]‐μ‐thio­cyanato]

The title complex, [Cu(C₁₁H₁₄BrN₂O)(NCS)]_n, is an inter­esting thio­cyanate‐bridged polynuclear copper(II) compound, which crystallizes with two independent mol­ecules in the asymmetric unit. Each Cu^II atom is five‐coordinate in a square‐pyramidal configuration, with one O and two N atoms of one Schiff base ligand and one terminal N atom of a bridging thio­cyanate ligand defining the basal plane, and one terminal S atom of another bridging thio­cyanate ligand occupying the apical position. The {4‐bromo‐2‐[2‐(dimethyl­amino)ethyl­imino­meth­yl]phenolato}copper(II) units are linked by the bridging thio­cyanate ligands, forming polymeric chains running along the a axis. There are weak inter­molecular C—H⋯O and C—H⋯S hydrogen bonds between the chains in the crystal structure.     

Methyl (SR)‐10‐chloro‐1,2,3,4,5,6‐hexahydro‐6‐hydroxy‐8‐methoxy‐1‐methyl‐1,9‐phenanthroline‐6‐carboxylate

In the title compound, C₁₆H₁₉ClN₂O₄, the pyridine ring is nearly planar, the piperidine ring is non‐planar and the cyclo­hexane ring adopts a screw‐boat conformation. The carboxyl­ate group makes a dihedral angle of 80.9 (2)° with the least‐squares plane through the cyclo­hexane ring.     

{(E)‐ and {(Z)‐2‐[α,β‐bis­(methoxy­carbonyl)­vinyl]­cyclo­pentadien‐1‐yl­idene}tri­phenyl­phospho­rane

The Ramirez yl­ide undergoes electrophilic substitution with di­alkyl acetyl­ene­di­carboxyl­ates, yielding a mixture of the Z and E adducts. The crystal structure analyses of the two adducts formed using di­methyl­acetyl­ene, viz. di­methyl (E)‐ and (Z)‐1‐[2‐(tri­phenyl­phospho­ranyl­idene)­cyclo­pentadien‐1‐yl]­ethyl­ene­di­carboxyl­ate, both C₂₉H₂₅O₄P, explain an unusual chemical shift observed for the vinyl H atom of the Z adduct, which had previously precluded a definitive assignment of the isomers. In addition, the structures explain why only one of the isomers reacts further with acetyl­ene esters to produce azulenes with a rare substitution pattern.     

Four bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutan‐1‐yl)oligosulfanes

The four oligosulfanes, bis(1‐chloro‐2,2,4,4‐tetra­methyl‐3‐oxo­cyclo­butan‐1‐yl)­disulfane, C₁₆H₂₄Cl₂O₂S₂, (III), 1,3‐bis(1‐chloro‐2,2,4,4‐tetra­methyl‐3‐oxo­cyclo­butan‐1‐yl)­trisulfane, C₁₆H₂₄Cl₂O₂S₃, (V), 1,4‐bis(1‐chloro‐2,2,4,4‐tetra­methyl‐3‐oxo­cyclo­butan‐1‐yl)­tetrasulfane, C₁₆H₂₄Cl₂O₂S₄, (VII), and 1,6‐bis(1‐chloro‐2,2,4,4‐tetra­methyl‐3‐oxo­cyclo­butan‐1‐yl)­hexasul­fane, C₁₆H₂₄Cl₂O₂S₆, (VIII), all have similar geometric parameters, with the C—C bond lengths involving the chloro‐substituted cyclo­butanyl C atom being elongated to about 1.59 Å. There are two mol­ecules in the asymmetric units of the tri‐ and tetrasulfanes, and the mol­ecules in the latter compound have local C₂ symmetry. The mol­ecule of the hexasulfane has crystallographic C₂ symmetry. Most of the cyclo­butanyl rings are not perfectly planar and have slight but varying degrees of distortion towards a flattened tetrahedron. The polysulfane chain in each structure has a helical conformation, with each additional S atom in the chain adding approximately one quarter of a turn to the helix.     

1‐Chloro‐3,6‐di­methoxy‐2,5‐di­methyl­benzene and 1‐chloro‐3,6‐di­methoxy‐2,4‐di­methyl­benzene

The title compounds, 1‐chloro‐3,6‐di­methoxy‐2,5‐di­methyl­benzene, (IIIa), and 1‐­chloro‐3,6‐di­methoxy‐2,4‐di­methyl­benzene, (IIIb), both C₁₀H₁₃ClO₂, were obtained from 2,5‐ and 2,6‐di­methyl‐1,4‐benzo­quinone, respectively, and are intermediates in the synthesis of ammonium quinone derivatives. The isomers have different substituents around the methoxy groups and crystallize in different space groups. In both mol­ecules, the methoxy groups each have different orientations with respect to the benzene ring. In both cases, one methoxy group lies in the plane of the ring and can participate in conjugation with the aromatic system, while the second is almost perpendicular to the plane of the aromatic ring. The C—O—C bond angles around these substituents are also different: 117.5 (4) and 118.2 (3)° in (IIIa) and (IIIb), respectively, when the methoxy groups lie in the plane of the ring, and 114.7 (3) and 113.6 (3)° in (IIIa) and (IIIb), respectively, when they are out of the plane of the ring.     

4,5,9,10‐Tetrahydro‐4‐methyl‐2‐phenyl‐9,10‐epoxy‐3H,10aH‐cyclobuta[a]benzo[2,3,4‐de]isoquinoline‐3,5‐dione

In the title compound, C₂₁H₁₅NO₃, which is one of the photoreaction products of N‐methyl‐1,8‐naphthalene­dicar­box­imide with phenyl­acetyl­ene, the cyclo­butene and epoxy rings are trans to each other across the cyclo­hexene ring of the tetralin moiety. The dihedral angle between the mean planes of the cyclo­butene and cyclo­hexene rings is 112.80 (2)°, while the latter makes a dihedral angle of 103.70 (9)° with the epoxy ring. The crystal structure is stabilized by C—H⋯O intermolecular interactions.     

Two packing motifs based upon chains of edge‐sharing PbI6 octa­hedra

The compounds catena‐poly[p‐phenyl­enediammonium [[diiodo­lead(II)]‐di‐μ‐iodo] dihydrate], {(C₆H₁₀N₂)[PbI₄]·2H₂O}_n, (I), and catena‐poly[bis­(3,5‐dimethyl­anilinium) [[diiodo­lead(II)]‐di‐μ‐iodo]], {(C₈H₁₂N)₂[PbI₄]}_n, (II), crystallize as organic–inorganic hybrids. As such, the structures consist of chains of [PbI₂]⁻ units extending along the c axis in (I) and along the b axis in (II). The asymmetric unit in (I) contains one Pb atom on a site of 2/m symmetry, two I atoms and a water molecule on mirror planes, and a p‐phenyl­enediammonium mol­ecule that sits around a site of 2/m symmetry with the C and N atoms on a mirror plane. In (II), the Pb atom is on a twofold axis and the two I atoms are on general positions. Each Pb atom is octa­hedrally coordinated to six I atoms, arranged as chains of edge‐sharing octa­hedra. Both compounds undergo hydrogen‐bonding inter­actions between the ammonium groups and the I atoms. In addition, there are hydrogen bonds between the water mol­ecules and the ammonium groups and halides in (I), and between the ammonium groups and the ring systems in (II).     

2‐{[Tris(hydroxymethyl)methyl]aminomethylene}cyclohexa‐3,5‐dien‐1(2H)‐one and its 6‐hydroxy and 6‐methoxy derivatives

The title compounds, 2‐{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}cyclo­hexa‐3,5‐dien‐1(2H)‐one, C₁₁H₁₅NO₄, (I), 6‐hydroxy‐2‐{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}­cyclo­hexa‐3,5‐dien‐1(2H)‐one, C₁₁H₁₅NO₅, (II), and 6‐methoxy‐2‐{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}­cyclo­hexa‐3,5‐dien‐1(2H)‐one, C₁₂H₁₇NO₅, (III), adopt the keto–amine tautomeric form, with the formal hydroxy H atom located on the N atom, and the NH group and oxo O atom display a strong intramolecular N—H⋯O hydrogen bond. The N—H⋯O hydrogen‐bonded rings are almost planar and coupled with the cyclo­hexa­diene rings. The carbonyl O atoms accept two other H atoms from the alcohol groups of adjacent mol­ecules in (I), and one from the alcohol and one from the phenol group in (II), but from only one alcohol H atom in (III).     

The addition‐reaction product of 1,1,1,4,4,4‐hexa­chloro‐1,4‐disila­butane with N‐methyl­imidazole

The product of the addition reaction of 1,1,1,4,4,4‐hexa­chloro‐1,4‐disila­butane with N‐methyl­imidazole is μ‐ethyl­ene‐C¹:C²‐bis­[di­chloro­tris(1‐methyl­imidazole‐N³)­silicon(IV)] dichloride, C₂₆H₄₀Cl₄N₁₂Si₂²⁺·2Cl^?. Two of the six Cl atoms are replaced by aromatic nitro­gen bases and the coordination sphere of silicon is extended from four to six. The mol­ecule is located on a crystallographic centre of inversion. The environment around the Si atom can be described as a slightly distorted octahedron with the Cl atoms occupying axial positions and the three N‐methyl­imidazole ligands and the ethyl­ene bridge in the equatorial plane.