Ethyl 2-cyano-2-{(Z)-2-[2,2-dicyano-1-(4-methylphenyl)ethyl]cyclohexylidene}acetate

In the title compound, C22H23N3O2, the cyclohexane ring adopts a chair conformation. The methylphenyl ring is oriented at an angle of 36.2 (1)° with respect to the best plane of cyclohexane moiety. In the crystal, molecules associate via C—H...N hydrogen bonds, forming a three-dimensional network.

New Bromo- and Iodo-Hydroxylactones with Two Methyl Groups Obtained by Biotransformation of Bicyclic Halolactones

The subject of the research was to determine the ability of the filamentous fungi to biotransform bicyclic halolactones containing two methyl groups in their structure. By chemical synthesis three bicyclic halolactones with two methyl groups, one in the cyclohexane ring and one in the lactone ring, were obtained: 2-chloro-4,7-dimethyl-9-oxabicyclo[4.3.0]nonan-8-one, 2-bromo-4,7-dimethyl-9-oxabicyclo[4.3.0]nonan-8-one, and 2-iodo-4,7-dimethyl-9-oxabicyclo[4.3.0]nonan-8-one. These compounds were formed as mixtures of two diastereoisomers. The obtained halolactones (as mixture of two diastereoisomers) were subjected to screening biotransformation with the use of eight strains of filamentous fungi: Fusarium culmorum AM10, F. avenaceum AM12, F. semitectum AM20, F. solani AM203, Absidia coerulea AM93, A. cylindrospora AM336, Penicillium chermesinum AM113, P. frequentans AM351. Two of the substrates, 2-bromo-4,7-dimethyl-9-oxabicyclo[4.3.0]nonan-8-one and 2-iodo-4,7-dimethyl-9-oxabicyclo[4.3.0]nonan-8-one, were hydroxylated without removing the halogen atom from the molecule, giving 2-bromo-7-hydroxy-4,7-dimethyl-9-oxabicyclo[4.3.0]nonan-8-one, 2-bromo-5-hydroxy-4,7-dimethyl-9-oxabicyclo[4.3.0]nonan-8-one, and 2-iodo-7-hydroxy-4,7-dimethyl-9-oxabicyclo[4.3.0]nonan-8-one as products. The hydroxylation capacity was demonstrated by strains of Absidia cylindrospora AM336, Fusarium avenaceum AM12, and F. solani AM203. The structures of all lactones were determined on the basis spectroscopic data.

Diastereopure Synthesis of Novel Cyclohexane-Ring-Based Constrained Lanthionine and α-Methyllanthionine through an SN2 Reaction with a β-Bromoalanine as a Key Step

Here we report the diastereopure synthesis of a novel protected lanthionine derivative substituted with a cyclohexane ring as well as the diastereopure synthesis of an α-methyllanthionine derivative. By starting from enantiopure α,β-cyclohexane-substituted cystine, or α-methylcysteine, we designed a straightforward route that permits the preparation of orthogonally protected modified lanthionines in diastereopure form. The key step of the methodology is the formation of a thioether bond through the use of an β-bromoalanine derivative. The strategy developed should be valuable in the preparation of a wide range of modified constrained lanthionines that might be finally attached to a peptide sequence, which would be especially useful in the syntheses of novel lantibiotics.

Transposition of Aromaticity from a Furan to a Cyclohexane Ring in Furoisoindoles During the Interaction of 3-(Furyl)allylamines with Bromomaleic Anhydride

An unexpected four-step reaction sequence was discovered in the course of investigation of the interaction between 3-(furan-2-yl)allylamines and bromomaleic anhydride. This conversion begins with the initial N-acylation of the allylamines by the anhydride, followed by intramolecular Diels–Alder reaction, which is accompanied by a dehydrohalogenation, and ends with the formation of partially unsaturated furo[2,3-f]isoindoles followed by transposition of aromaticity from the furan moiety to the neighboring cyclohexane ring. The reaction between 3-(furan-3-yl)allylamines and bromomaleic anhydride does not stop at a furo[2,3-f]isoindole formation step, but proceeds further with the cleavage of the furan ring in a 100% atom-efficient fashion to provide polysubstituted isoindoline-4-carboxylic acids.

Chemoenzymatic Synthesis of Enantiomeric, Bicyclic δ-Halo-γ-lactones with a Cyclohexane Ring, Their Biological Activity and Interaction with Biological Membranes

Starting from 1-acetyl-1-cyclohexene, three enantiomeric pairs (ee ≥ 99%) of bicyclic δ-halo-γ-lactones with cyclohexane ring were obtained in five-step synthesis. The key stereochemical steps were lipase-catalyzed kinetic resolution of racemic 1-(cyclohex-1-en-1-yl) ethanol followed by transfer of chirality to ethyl 2-(2-ethylidenecyclohexyl) acetate in the Johnson–Claisen rearrangement. Synthesized halolactones exhibited antiproliferative activity towards canine B-cell leukemia cells (GL-1) and canine B-cell chronic leukemia cells (CLB70) and the most potent (IC50 18.43 ± 1.46 μg/mL against GL-1, IC50 11.40 ± 0.40 μg/mL against CLB70) comparable with the control etoposide, was (1R,6R,1′S)-1-(1′-chloroethyl)-9-oxabicyclo[4.3.0]nonan-8-one (8b). All halolactones did not have a toxic effect on erythrocytes and did not change the fluidity of membranes in the hydrophobic region of the lipid bilayer. Only weak changes in the hydrophilic area were observed, like the degree of lipid packing and associated hydration. The racemic halolactones were also tested for their antimicrobial properties and found to exhibit selectivity towards bacteria, in particular, towards Proteus mirabilis ATCC 35659.

Crystal structure of (E)-N-cyclohexyl-2-(2-hydroxy-3-methylbenzylidene)hydrazine-1-carbothioamide

The asymmetric unit of the title compound, C15H21N3OS, comprises of two crystallographically independent molecules (A and B). Each molecule consists of a cyclohexane ring and a 2-hydroxy-3-methylbenzylidene ring bridged by a hydrazinecarbothioamine unit. Both molecules exhibit an E configuration with respect to the azomethine C=N bond. There is an intramolecular O—H...N hydrogen bond in each molecule forming an S(6) ring motif. The cyclohexane ring in each molecule has a chair conformation. The benzene ring is inclined to the mean plane of the cyclohexane ring by 47.75 (9)° in molecule A and 66.99 (9)° in molecule B. The mean plane of the cyclohexane ring is inclined to the mean plane of the thiourea moiety [N—C(=S)—N] by 55.69 (9) and 58.50 (8)° in molecules A and B, respectively. In the crystal, the A and B molecules are linked by N—H...S hydrogen bonds, forming `dimers'. The A molecules are further linked by a C—H...π interaction, hence linking the A–B units to form ribbons propagating along the b-axis direction. The conformation of a number of related cyclohexanehydrazinecarbothioamides are compared to that of the title compound.

A minimal structural variation can overcome tumour resistance of oxaliplatin: the case of 4,5-dehydrogenation of the cyclohexane ring

A new family of anticancer compounds has been derived from oxaliplatin by inserting a double-bond between carbons 4 and 5 of the 1,2-diaminocyclohexane ring.

Crystal structures of two 1,3-thiazolidin-4-one derivatives featuring sulfide and sulfone functional groups

The crystal structures of two closely related compounds, 1-cyclohexyl-2-(2-nitrophenyl)-1,3-thiazolidin-4-one, C15H18N2O3S, (1) and 1-cyclohexyl-2-(2-nitrophenyl)-1,3-thiazolidin-4-one 1,1-dioxide, C15H18N2O5S, (2), are presented. These compounds are comprised of three types of rings: thiazolidinone, nitrophenyl and cyclohexyl. In both structures, the rings are close to mutually perpendicular, with interplanar dihedral angles greater than 80° in each case. The thiazolidinone rings in both structures exhibit envelope puckering with the S atom as flap and the cyclohexyl rings are in their expected chair conformations. The two structures superpose fairly well, except for the orientation of the nitro groups with respect to their host phenyl ring, with a difference of about 10° between 1 and 2. The extended structure of 1 has two kinds of weak C—H...O interactions, giving rise to a closed ring formation involving three symmetry-related molecules. Structure 2 has four C—H...O interactions, two of which are exclusively between symmetry-related thiazolidinone dioxide moieties and have a parallel `give-and-take-fashion' counterpart. In the other two interactions, the nitrophenyl ring and the cyclohexane ring each offer an H atom to the two O atoms on the sulfone group. Additionally, a C—H...π interaction between a C—H group of the cyclohexane ring and the nitrophenyl ring of an adjacent molecule helps to consolidate the structure.

Crystal structure of (E)-2-[3-(tert-butyl)-2-hydroxybenzylidene]-N-cyclohexylhydrazine-1-carbothioamide

In the title compound, C18H27N3OS, the cyclohexane ring has a chair conformation. The azomethine C=N double bond has an E configuration. The nearly planar hydrazinecarbothioamide moiety and substituted benzene ring are twisted by 31.13 (5)° relative to each other. The amide moiety and the cyclohexane ring are almost perpendicular to each other; a similar conformation was previously observed in reported structures. In the crystal, molecules are linked by N—H...S hydrogen bonds, forming inversion dimers with an R 2 2(8) ring motif.