Cyclohepten-5-one

W. Pitsch, A. Russel, M. Zabel, and B. Konig, Synthesis of a functionalized cyclohepten-one from erythronic acid-4-lactone, Tetrahedron, 57 (2001) 2345-2347. 

These results can be explained in terms of an interplay of stereoelectronic and steric factors. Steric factors are evidently more important in the reaction of bulky cuprate clusters than in the Sakurai reaction. Thus stereoelectronic factors predominate in the allylsilane reaction. Similar effects are observed in conjugate additions to substituted cyclohepten-ones. 

A series of (2+2) photocycloaddition reactions have been carried out using (5R)-5-menthyloxy-2(5H)-furanone (32) as the substrate. Photoaddition of cyclopentenone to this substrate gives the four products (33)-(36) with some level of regioselectivity but no facial selectivity. Interestingly, cyclohexenone, cyclohepten-one and cyclooctenone fail to undergo the mixed addition. High facial selectivity is observed when more complex enones such as the 3,5,5-trimethylcyclohexenone and isophorone, (37) are used. The reaction affords adducts of the type illustrated... 

Oxime 26 was prepared from 5,ll-dihydro-dibenzo[a,d]cyclohepten-10-one. The Hoch-Campbell reaction of 26 with 3-dimethylaminopropylmagnesium bromide produced aziridine 27 in 46% yield after acidic workup. Extension of the Hoch-Campbell reaction to steroids has also been reported. Thus, treatment of 3(3-hydroxy-5-pregnen-20-one oxime (28) with methylmagnesium iodide furnished a mixture of diastereomers, 20ot/20P,21-imino-20-methyl-5-pregnen-3P-ol (29) in a 50% combined yield and a 3 1 ratio. On the other hand, homo-adamantan-4-one oxime (30) was transformed to homo-adamantano[4,5-b]-2 -ethylaziridine (31) in 76% yield upon the action of... 

Phthalic anhydride is reacted with phenylacetic acid to form 3-benzylidenephthalide which is then hydrogenated to 2-phenethylbenzoic acid. Conversion to the acid chloride followed by intramolecular dehydrochlorination yields the ketone, 5H-dibenzo[a,d] cyclohepten-5-one. The ketone undergoes a Grignard reaction with 3-(dimethylamino)propyl chloride to give 5-(7-dimethylaminopropylidene)-5H-dibenzo[a,d] cycloheptene. 

N-Methyl-4-chloropiperidine Polyphosphoric Acid 4-Aza-10,11 -dihydro-5-H-dibenzo-[a,d] -cycloheptene-5 one... 

Preparation of 4-aza-S-(N-methyl-4-piperidyll-10,11-dihydro-SH-dibenzo[a,d]cycloheptene-S-ol Add 17.4 g of N-methyl-4-chloropiperidine to a stirred mixture containing 3.2 g of magnesium, 20 ml of anhydrous tetrahydrofuran, 1 ml of ethyl bromide and a crystal of iodine. Reflux for two hours, cool to 30°-35°C and add a solution of 13 g of 4-aza-10,11 -dihydro-5H-dibenzo[a,d] cycloheptene-5-one in 25 ml of tetrahydrofuran. Stir for five hours, remove the solvent by distillation in vacuo and add 250 ml of ether. Add 100 ml of 10% ammonium chloride solution and extract the mixture with chloroform. Concentrate the chloroform solution to a residue and recrystallize from isopropyl ether obtaining 20 g of the carbinol,... 

In an initial step, dibenzo[a,d] cyclohepten-5-one is reacted with the Grignard reagent of 3-di-methylaminopropyl chloride and hydrolyzed to give 5-(3-dimethylaminopropyl)-dibenzo[a,d] -[1,4] cycloheptatriene-5-ol. Then 13 g of that material, 40 ml of hydrochloric acid, and 135 ml of glacial acetic acid is refluxed for 314 hours. The solution is then evaporated to dryness in vacuo and added to ice water which is then rendered basic by addition of ammonium hydroxide solution. Extraction of the basic solution with chloroform and removal of the solvent from the dried chloroform extracts yields the crude product which when distilled in vacuo yields essentially pure 5-(3-dimethylaminopropylidene)-dibenzo[a/f ] [ 1,4] cycloheptatriene, BP 173°C to 177°C at 1.0 mm. 

Chemical Name 10,11-dihydro-5H-diben2o[a,d] cyclohepten-5-one 0-[2-(dimethylamino)-ethyl] oxime... 

To 3.8 g of 2-methyl-3-(10,11-dihydro-5H-dibenzo[a,d] cycloheptene-5-ylidene)-1-pyr-roline, there were added 8 g of ethyl iodide. This mixture was placed into a closed vessel and heated at 80°C in a water-bath for one hour. After completing the reaction, the reaction mix-... 

Dibenzo[a,dlcyclohepta-1,4-diene-5-one Amitriptylin oxide Dibenzo[a,el cycloheptatrien-5-one Cyproheptadine 5H-Dibenzo (a,d 1 cycloheptene Protriptyline... 

Cyclohepten-l-one has been prepared from cycloheptanone by dehydrohalogenation of the ethylene ketals of 2-chloro- and 2-bromocycloheptanone and subsequent hydrolysis. The a,)3-dehydrogenation of cycloheptanone has also been effected via the... 

ONE-CARBON RING EXPANSION OF CYCLOALKANONES TO CONJUGATED CYCLOALKENONES 2-CYCLOHEPTEN-l-ONE... 

However, as illustrated in Scheme 2.112, the reaction of ylide 2-490 with 4-hexen-3-one (2-491) did not lead to the expected cycloheptene, but to the cyclopropane derivative 2-493 in 98% yield by a simple addition of the ylide to 2-491 to give 2-492... 

The energy differences seem to be somewhat unrealistic, specifically if one considers that 15, 16, and 17 can be regarded as analogues of trans-cyclo-pentene, /rani-cyclohexene, and respectively, as frans-cycloheptene.12 As has... 

Amitriptyline Amitriptyline, 5-(3-dimethylaminopropyliden)-10,ll-dihydrodibenzocy-cloheptene (7.1.4), differs from imipramine in that the nitrogen atom in the central part of the tricyclic system is replaced by a carbon, which is bound to a side chain by a double bond. Amitriptyline (7.1.4) is synthesized by interaction of 10,ll-dihydro-A,iV-dimethyl-57f-dibenzo[a,d]cyclohepten-5-one with 3-dimethylaminopropyhnagnesium bromide and the subsequent dehydration of the resulting tertiary alcohol (7.1.3) using hydrochloric acid [ 11]. 

Cyclobenzaprine Cyclobenzaprine, A,lV-dimethyl-3 -(dibenzo[a,d]cyclohepten-5-ylidene) propylamine (15.3.9), is synthesized by reacting 5//-dibenzo[a,d]cyclohepten-5-one with 3-dimethylaminopropyhnagnesium chloride and subsequent dehydration of the resulting carbinol (15.3.8) in acidic conditions into cyclobenzaprine (15.3.9) [30-32]. 

Cyproheptadine Cyproheptadine, 4-(dibenzo[a,d]cyclohepten-5-ylidene)-l-methylpipe-ridine (16.1.21), is synthesized by reacting l-methyl-4-magnesiumchloropiperidine with 5H-dibeno[a,d]cycloheptene-5-one, which forms carbinol (16.1.20), the dehydration of which in an acidic medium leads to the formation of cyproheptadine (16.1.21) [39,40]. 

The related dirhodium(II) a-caprolactamate (cap) complex [Rh2(p--cap)4] undergoes a one-electron oxidation process at quite a lower potential (11 mV) than the acetate complex (1170 mV). In agreement with the Kochi hypothesis, the a-caprolactamate complex has recently been found to be an exceptional catalyst for the allylic oxidation of alkenes under mild conditions. A wide range of cyclohexenes, cycloheptenes, and 2-cycloheptenone (Eq. 5) are rapidly converted to enones and enediones in 1 h with only 0.1 mol % of [Rh2( x-cap)4] and yields ranging from 60 to 90%, in the presence of potassium carbonate [34]. 

Photocycloadditions of naphthalene derivatives to alkcnes have been recently reviewed.60 Examples of such reactions are the photocycloaddition of naphthalene to 2,3-dihy-drofuran,61 of 4-methoxy-l-naphthonitrile to acrylonitrile62 and of 2-trimethylsiloxynaph-thalene to methyl acrylate.63 2-Naphthols undergo cycloaddition with ethene in the presence of aluminum trihalides only.64 Other bicyclic aromatic compounds, e.g. A-acylindoles65-67 and /V-methylphenanthrene-9,10-dicarboximide,68 have also been studied in detail. Irradiation of 5/f-dibenzo[u,i7]cyclohepten-5-one (21) and dimethyl 2-methylfumarate (22) in dioxane gives the cyclobutane adduct 23 in 73% yield.69... 

However the existence of the bromine co-product is speculative and has not been experimentally verified. The reaction may be regarded as a one electron oxidation by the S i. Me , )2 aminyl radical, and it is interesting to note that aminyl radical complexes of transition metals such as [Rh(Ntrop2)(bipy)][OTf]5 (trop = 5-H-dibenzo[a,d]cycloheptene) have been isolated. The manganese and cobalt compounds were the first examples of three-coordinate Mn(lll) and Co(lll) complexes to have been structurally characterized. 

Dibenzofuro[4,5-c]tropone (8H-dibenzo[a,e]furo[3,4-c]cyclohepten-8-one 368, X = CO) and the corresponding thiepin-5,5-dioxide (8//-dibenzo-[6,/]furo[3,4-retro Diels-Alder route. In refluxing benzene, the intermediate (367, X = CO) can be isolated. Further routes to 368 (X = CO) by retro Diels-Alder reaction exist. The 1-methyl derivative of 368 (X = CO) has been trapped as a maleic anhydride adduct. ... 

Reaction of acetyl hypofluorite with 5//-dibenzo[n. r/]cyclohepten-5-one gives the. vm-adduct 8 trifluoroacetyl hypofluorite appears to be too reactive and only tars are produced. 0... 

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