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A new prenylated 3-benzoxepin derivative, elsholtzioxin (1), together with fifteen known compounds (2–16) were isolated from the whole parts of Elsholtzia penduliflora. Their structures were elucidated on the basis of various spectroscopic techniques and chemical evidences. The antiviral activities of these compounds were evaluated in vitro. The new compound (1) exhibited potential anti-influenza virus activity against strain A/WSN/33/2009 (H1N1) with inhibition rate of 47.19%. Compounds 2, 9 and 12 exhibited significant inhibitory activities with IC50 value of 26.16, 34.66 and 20.81 μM, respectively.

Estrogen receptor α (ERα) is an important target for the design of drugs such as tamoxifen (2a) and fulvestrant (5). Three series of ER-ligands based on the benzoxepin scaffold structure were synthesized: series I containing an acrylic acid, series II with an acrylamide, and series III with a saturated carboxylic acid substituent. These compounds were shown to be high affinity ligands for the ER with nanomolar IC50 binding values. Series I acrylic acid ligands were generally ERα selective. In particular, compound 13e featuring a phenylpenta-2,4-dienoic acid substituent was shown to be antiproliferative and downregulated ERα and ERβ expression in MCF-7 breast cancer cells. Interestingly, from series III, the phenoxybutyric acid derivative compound 22 was not antiproliferative and selectively downregulated ERβ. A docking study of the benzoxepin ligands was undertaken. Compound 13e is a promising lead for development as a clinically relevant SERD, while compound 22 will be a useful experimental probe for hel...

A short and efficient method was developed for the synthesis of 2-benzoxepin-3(1H)-ones. The synthetic sequence comprises of initial intermolecular Heck coupling, followed by reduction of the carbonyl functionality of the Heck product and finally base-induced intramolecular condensation. Notably, the final condensation may proceed by an interesting oxy-Michael addition, cycloreversion via double bond isomerization and intramolecular condensation.

A one-pot synthesis of multisubstituted 2,3-dihydro-1H-2-benzazepin-1-ones and 3H-2-benzoxepin-1-ones by an I-MCR/Wittig sequence was developed. The reaction of phosphonium salt 3, arylglyoxals 4, amine 5 (or without), and isocyanide 6 produced the 2,3-dihydro-1H-2-benzazepin-1-ones 8 or 3H-2-benzoxepin-1-ones 10 in good yields via a sequential Ugi or Passerini condensation and intramolecular Wittig reaction in the presence of NEt3.

Ovafolinins A and B, isolated from Lyonia ovalifolia var. elliptica, are lignans that contain a unique bridged structure containing a penta- and tetracyclic benzoxepin and an aryl tetralin. We report the first total synthesis of these natural products in which an acyl-Claisen rearrangement was initially utilized to construct the lignan backbone with correct relative stereochemistry. Judicious use of a bulky protecting group placed reactive moieties in the correct orientation, thereby resulting in a cascade reaction to form the bridged benzoxepin/aryl tetralin from a linear precursor in a single step. Modification of this route allowed the enantioselective synthesis of (+)-ovafolinins A and B, which confirmed the absolute stereochemistry, and comparison of optical rotation suggests that these compounds are found as scalemic mixtures in nature.

Dysfunctional signaling through the phosphoinositide 3-kinase (PI3K)/AKT/mTOR pathway leads to uncontrolled tumor proliferation. In the course of the discovery of novel benzoxepin PI3K inhibitors, we observed a strong dependency of in vivo antitumor activity on the free-drug exposure. By lowering the intrinsic clearance, we derived a set of imidazobenzoxazepin compounds that showed improved unbound drug exposure and effectively suppressed growth of tumors in a mouse xenograft model at low drug dose levels. One of these compounds, GDC-0032 (11l), was progressed to clinical trials and is currently under phase I evaluation as a potential treatment for human malignancies.

In this study, the synthesis of a series of novel four-fused-ring chromeno-benzoxepinones is described. The reaction of 1-benzoxepin-5-ones with salicylaldehydes mediated by 1,4diazabicyclo[2,2,2]octane (DABCO) involves domino reactions including an oxa-Michael reaction, an aldol condensation and dehydration in a one-pot sequence to yield the target compounds in fairly good yields.

Several methods for the preparation of 3,4-dihydro-1-benzoxepin-5 (2H)-ones are described. In addition to the desired ketones, a variety of novel by-products have been isolated

Thiophenol-mediated 7- endo radical cyclization for the synthesis of seven-membered cyclic ethers is described. This method can be successfully applied to synthesize various benzoxepin derivatives, which are present in many natural products as building blocks. Alkenyl radicals are generated from easily available terminal alkynes and thiophenol.

The estrogen receptors ERα and ERβ are recognized as important pharmaceutical targets for a variety of diseases including osteoporosis and breast cancer. A series of novel benzoxepin-derived compounds are described as potent selective modulators of the human estrogen receptor modulators (SERMs). We report the antiproliferative effects of these compounds on human MCF-7 breast tumor cells. These heterocyclic compounds contain the triarylethylene arrangement as exemplified by tamoxifen, conformationally restrained through the incorporation of the benzoxepin ring system. The compounds demonstrate potency at nanomolar concentrations in antiproliferative assays against an MCF-7 human breast cancer cell line with low cytotoxicity together with low nanomolar binding affinity for the estrogen receptor. The compounds also demonstrate potent antiestrogenic properties in the human uterine Ishikawa cell line. The effect of a number of functional group substitutions on the ER binding properties of the benzoxepin molecular scaffold is examined through a detailed docking and 2D-QSAR computational investigation. The best QSAR model developed for ERαβ selectivity yielded R2 of 0.84 with an RMSE for the training set of 0.30. The predictive quality of the model was Q2 of 0.72 and RMSE of 0.18 for the test set. One particular compound (26b) bearing a 4-fluoro substituent, exhibits 15-fold selectivity for ERb and both our docking and QSAR studies converge on the correlation between enhanced lipophilicity and enhanced ERb binding for this benzoxepin ring scaffold. Refereed/Peer-reviewed

Two new stilbene derivatives, (E)-2′,3,3′-trihydroxy-5-methoxystilbene (1, Pholidotol C) and (Z)-3,3′-hydroxy-5-methoxystilbene (2, Pholidotol D), were isolated from the air-dried whole plant of Pholidota chinensis Lindl., together with eight known dihydrophenanthrene derivatives, lusianthridin (3), cannabidihydrophenanthrene (4), coelonin (5), hircinol (6), erianthridin (7), 4,5-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (8), eulophiol (9), and 2,4,7-trihydroxy-9,10-dihydrophenanthrene (10), and a benzoxepin derivative bulbophylol B (11). Their inhibitory effects on nitric oxide (NO) production activity and 1,1-diphenyl-2-picrylhydrazil radical-scavenging activity were examined. Among these compounds, 11 exhibited the most potent activity toward NO production inhibition activity and radical-scavenging activity; moreover, 11 reduced inducible nitric oxide synthase mRNA expression.

Starting from ortho-bromobenzaldehydes or -acetophenones, The three-step synthesis comprises Heck coupling with ethyl acrylate, reduction of the carbonyl group to an alcohol function and base-mediated cyclization.

[structures: see text] Two naturally occurring 3-methyl-2,5-dihydro-1-benzoxepin carboxylic acids, 6-hydroxy-3-methyl-8-(phenylethyl)-2,5-dihydro-1-benzoxepin-9-carboxylic acid (radulanin E) (1) and 9-hydroxy-3-methyl-2,5-dihydro-1-benzoxepin-7-carboxylic acid (2), were synthesized using Stille coupling followed by Mitsunobu cyclization.

The first unambiguous observation of an oxepin-2,3-oxide is reported. Between 5 and 10 °C it rearranges rapidly to its isomer 1H-2-benzopyran-1-carboxaldehyde. In contrast, 2,3-oxides of monocyclic oxepins rearrange to stable, ring-opened dialdehydes or diketones.

The synthesis and pharmacological evaluation of cis- and trans-6-amino-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ols 4a-c and 5a-c and cis- and trans-4-amino-2,3,4,5-tetrahydro-1-benzoxepin-5-ols 4d-f and 5d-f were carried out. Chemo- and stereoselective synthesis of 5a-f was achieved by reduction of corresponding alpha-amino ketones 3a-f with LiAl(t-BuO)3H. cis-4-Amino-2,3,4,5-tetrahydro-1-benzoxepin-5-ol 4d and trans-4-amino-2,3,4,5-tetrahydro-1-benzoxepin-5-ol 5d exhibited marked anorexigenic activity in mice at a dose of LD50 800 and 500 mg/kg and ED50 75 and 55 mg/kg, respectively, while the analog cis-2,3-dihydroxy-6-amino-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ol 8 showed typical alpha-sympathomimetic activity.

The chlorinated 1-benzoxepin derivative pterulone ( 1a ), a potent antifungal metabolite isolated from a Pterula species, was synthesised from 4,5-dihydro-2 H -benzoxepin-3-one 6 by the oxidation of 6 to 3(2 H )-oxepinone 7 , a Wittig reaction that transformed the keto functionality of 7 to a chlorovinyl group, and a Friedel Craft's acetylation. The mixture of E and Z isomers ( 1a and 1b ) obtained could transformed to pure pterulone ( 1a ) by photochemical isomerisation and separation by chromatography. The yield was 23% starting from 6 .

By treatment of sodium nitronate salts of 5-glyco-4-nitrocyclohexenes with hydrochloric acid, five new bicyclic ethers with six-membered rings fused to five-, seven-, or eight-membered rings have been synthesized; also a mechanism for their formation is proposed. Structural elucidation of the new compounds is based on spectroscopic data, as well as on their comparison with those of closely related substances.

Cuparene-type sesquiterpenes were isolated from a culture broth of Flammulina velutipes (Curt.:Fr.) Sing. Using spectroscopic methods (HR-MS, 1H and 13C NMR, and 2D NMR, spectroscopy), their structures were determined to be 2,3,4,5-tetrahydro-2,7-dihydroxy-5,8,10,10-tetramethyl-2,5-methano-1- benzoxepin and 5-methyl-2-(3-oxo-1,2,2-trimethylcyclopentyl)benzoquinone. Both showed antimicrobial activity against Cladosporium herharum and Bacillus subtilis.

Bioisosteric replacement of the C-6 carbon atom in piperidine I and piperazine II with S, O, and N heteroatoms is described. Amide and cyanoguanidine derivatives of these compounds were evaluated in vitro and found to be good inhibitors of farnesyl-protein transferase. An improved method of preparing the 5,11-dihydro-[1]-benzthiepin nucleus 6 was accomplished in high yield and with excellent regioselectivity using an AlCl3 melt protocol.

The title compound, C22H23FO6, is an unexpected product of the fluorination of podophyllol. The absolute configuration was determined from the known configuration of the synthetic precursor. Non-classical C—H⋯O hydrogen bonds link the mol­ecules in the crystal structure into sheets parallel to (001).

International audience; A series of novel benzoxepins 6 was designed and prepared as rigid-isoCA-4 analogues according to a convergent strategy using the coupling of N-tosylhydrazones with aryl iodides under palladium catalysis. The most potent compound 6b, having the greatest resemblance to CA-4 and isoCA-4 displayed antiproliferative activity at nanomolar concentrations against various cancer cell lines and inhibited tubulin assembly at a micromolar range. In addition, benzoxepin 6b led to the arrest of HCT116, K562, H1299 and MDA-MB231 cancer cell lines in the G2/M phase of the cell cycle, and strongly induced apoptosis at low concentrations. Docking studies demonstrated that benzoxepin 6b adopt an orientation similar to that of isoCA-4 at the colchicine binding site on -tubulin.

Nine 1,3,4,5-tetrahydro-2-benzoxepin derivatives have been prepared as mimics of the folded (gauche) conformation of cyclamenaldehyde (1) and related compounds, but none of them showed the typical lily-of-the valley (muguet) odour activity. However, conversion of these substances to previously unknown analogues of 1 having a Me substituent on the aromatic ring in an ortho position to the side chain led to new fragrance substances with remarkable properties. The results indicate that the extended (anti) conformation is more likely to be the ‘bioactive’ one at the receptor site(s).

A series of N-hydroxyurea derivatives based on substituted benzoxepin and benzothiepin templates was prepared and the compounds were evaluated for their ability to inhibit 5-lipoxygenase in vitro and ex vivo.

Of the four class I phosphoinositide 3-kinase (PI3K) isoforms, PI3Kα has justly received the most attention for its potential in cancer therapy. Herein we report our successful approaches to achieve PI3Kα vs PI3Kβ selectivity for two chemical series. In the thienopyrimidine series of inhibitors, we propose that select ligands achieve selectivity derived from a hydrogen bonding interaction with Arg770 of PI3Kα that is not attained with the corresponding Lys777 of PI3Kβ. In the benzoxepin series of inhibitors, the selectivity observed can be rationalized by the difference in electrostatic potential between the two isoforms in a given region rather than any specific interaction.

Syntheses of spiro[2,3-dihydro-4H-1-benzopyran-4,1'-cyclohexan]-2-one derivatives by reaction sequences including a radical reaction and a total synthesis of (±)-lycoramine (2) are described. Radical reactions (Bu 3 SnH, AIBN) of 1-[(1'-cyclohexenylmethyl)oxy]-2-halobenzenes 23b-d in boiling benzene gave the corresponding spiro[2,3-dihydrobenzofuran-3,1'-cyclohexanes] 26a,b in good yields, whereas the reaction of 1-(1'-cyclohexenylethoxy)-2-bromobenzene (25) under similar conditions afforded a mixture of spiro[2,3-dihydro-4H-1-benzopyran-4,1'-cyclohexane] 27 and benzoxepin 28. Furthermore, the radical reaction of ethyl 2-[(2'-bromoaryl)oxy]-1-cyclohexenylacetate 37a produced ethyl 2-spiro[2,3-dihydrobenzofuran-3,1'-cycloexane]carboxylate 38 in good yield. Compound 38 was converted to spiro[2,3-dihydro-4H-1-benzopyran-4,1'-cyclohexane]-2,4'-dione 40 by treatment with SmI 2 and then with 3 N HCl. Spiro[2,3-dihydro-4H-1-benzopyran-4,1'-cyclohexane]-2,4'-dione 40 was transformed to (±)-lycoramine (2) in four steps in 43% overall yield

Syntheses of spiro[2,3-dihydro-4H-1-benzopyran-4,1'-cyclohexan]-2-one derivatives by reaction sequences including a radical reaction and a total synthesis of (±)-lycoramine (2) are described. Radical reactions (Bu 3 SnH, AIBN) of 1-[(1'-cyclohexenylmethyl)oxy]-2-halobenzenes 23b-d in boiling benzene gave the corresponding spiro[2,3-dihydrobenzofuran-3,1'-cyclohexanes] 26a,b in good yields, whereas the reaction of 1-(1'-cyclohexenylethoxy)-2-bromobenzene (25) under similar conditions afforded a mixture of spiro[2,3-dihydro-4H-1-benzopyran-4,1'-cyclohexane] 27 and benzoxepin 28. Furthermore, the radical reaction of ethyl 2-[(2'-bromoaryl)oxy]-1-cyclohexenylacetate 37a produced ethyl 2-spiro[2,3-dihydrobenzofuran-3,1'-cycloexane]carboxylate 38 in good yield. Compound 38 was converted to spiro[2,3-dihydro-4H-1-benzopyran-4,1'-cyclohexane]-2,4'-dione 40 by treatment with SmI 2 and then with 3 N HCl. Spiro[2,3-dihydro-4H-1-benzopyran-4,1'-cyclohexane]-2,4'-dione 40 was transformed to (±)-lycoramine (2) in four steps in 43% overall yield

A novel rearrangement of dithianylcyclobutachromanol derivative 3a on treatment with mercuric oxide and fluoroboric acid in aqueous tetrahydrofuran leads to 1,2,2a,8,9,9a-hexahydro-2a,9a-dimethylcyclobuta[b]-[1]benzoxepin-8,9-dione whose structure is established by X-ray analysis.

Two novel monochlorinated 2,3-dihydro-1-benzoxepin derivatives were isolated from the ethyl acetate extracts of the stipes of Mycena galopus. The structures were established on the basis of their spectral data.

The chlorinated 1-benzoxepin derivative pterulone ( 1a ), a potent antifungal metabolite isolated from a Pterula species, was synthesised from 4,5-dihydro-2 H -benzoxepin-3-one 6 by the oxidation of 6 to 3(2 H )-oxepinone 7 , a Wittig reaction that transformed the keto functionality of 7 to a chlorovinyl group, and a Friedel Craft's acetylation. The mixture of E and Z isomers ( 1a and 1b ) obtained could transformed to pure pterulone ( 1a ) by photochemical isomerisation and separation by chromatography. The yield was 23% starting from 6 .

We have synthesized a series of polymethoxylated rigid analogs of combretastatin A-4 which contain a benzoxepin ring in place of the usual ethylene bridge present in the natural combretastatin products. The compounds display antiproliferative activity when evaluated against the MCF-7 and MDA human breast carcinoma cell lines. 5-(3-Hydroxy-4-methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-2,3-dihydro-benzoxepine (11g) was found to be the most potent product when evaluated against the MCF-7 breast cancer cell line. A brief computational study of the structure-activity relationship for the synthesized compounds is presented. These 4,5-diarylbenzoxepins are identified as potentially useful scaffolds for the further development of antitumor agents which target tubulin. Refereed/Peer-reviewed

By treatment of ethyl 4- or 5-substituted 2-acetylphenoxyacetates 1 with potassium hydroxide in dry dioxane, benzofurans 2–7 and 2,3,4,5-tetrahydro-1-benzoxepin-3,5-diones 8 were obtained. The relative yields of benzofurans 2–7 and 2,3,4,5-tetrahydro-1-benzoxepin-3,5-diones 8 varied with the types of 4- or 5-substituents. The electron-donating 4-methoxyl group favored the formation of benzoxepins. On the other hand, electron-withdrawing substituents such as the 4-nitro group favored the formation of benzofurans. When esters 1 were treated with sodium amide, 2,3-dihydrobenzofurans 2 were obtained exclusively regardless of 4- or 5-substituents.