1453-06-1Relevant articles and documents
A new synthesis of 5,8-dimethyl-2-tetralone - A potential intermediate for the synthesis of ring-A aromatic sesquiterpenes. Novel transformation during acetoxylation of 5,8-dimethyldihydronapthalene
Banerjee, Ajoy K.,Vera, William,Laya, Manuel S.
, p. 2301 - 2308 (2004)
An efficient synthesis of 5,8-dimethyl-2-tetralone 4 starting from 5,8-dimethyl-1-tetralone 2 is described. It was converted into the unsaturated derivative 3, which on epoxidation followed by acid hydrolysis yielded tetralone 4. Acetoxylation of 3 with manganese(III) acetate and potassium bromide afforded dimethylnaphthalene 8 and derivative 9.
A new synthesis of occidol
Mane, Ramchandra Bhimrao,Kadam, Abhijit Jaysingrao
, p. 533 - 538 (1999)
Sodium borohydride reduction of 5,8-dimethyl-3,4-dihydronaphthalen-1-(2H)-one (4) yielded 5,8-dimethyl-1,2,3,4-tetrahydro-1-naphthol (5). The tetralol 5 on Vilsmeier-Haack reaction with N,N-dimethylacetamide yielded 1-(5,8-dimethyl-3,4-dihydro-2-naphthyl)
Synthesis of Medium-Ring-Sized Benzolactams by Using Strong Electrophiles and Quantitative Evaluation of Ring-Size Dependency of the Cyclization Reaction Rate
Kurouchi, Hiroaki,Ohwada, Tomohiko
, p. 876 - 901 (2019/12/30)
Benzolactams with medium-sized rings were synthesized via the electrophilic aromatic substitution reaction of carbamoyl cations (R1R2N+═C═O) in good to high yields without dilution. These reactions were utilized to quantitatively examine the extent of retardation of medium-sized ring formation, compared to five- or six-membered ring formation. The order of reaction rates of formation of cyclic benzolactams is six- > five- > seven- > eight- > nine-membered ring at 25 °C. The present reaction provides a route to eight- A nd nine-membered benzolactams.
Direct synthesis of γ-butyrolactones via γ-phenyl substituted butyric acids mediated benzyl radical cyclization
Mahmoodi,Jazayri
, p. 1467 - 1475 (2007/10/03)
Synthesis of several γ-butyrolactones with aromatic substitution at carbon 5 from comparative γ-aryl acids with 25-85% yield are covered. The straight oxidation in the presence of peroxydisulphate-copper(II)chloride system in aqueous medium was applied. The reaction is highly regioselective and leads exclusively to γ-butyrolactone, through stable benzylic radical intermediate.
SCHWEFELVERBINDUNGEN DES ERDOELS XV. METHYL-5,6,7,8-TETRAHYDRODINAPHTHOTHIOPHENE UND METHYLDINAPHTHOTHIOPHENE
Boberg, Friedrich,Jachiewicz, Adam,Garming, Alfons
, p. 1 - 12 (2007/10/02)
A one pot synthesis gives methyl-5,6,7,8-tetrahydrodinaphthothiophenes (7) from methyl-1,2,3,4-tetrahydronaphthalen-1-ones (1) by bromination and sulfurization.Tetrahydro compounds 7 have been dehydrogenated to corresponding dinaphthothiophenes 8.Proofs for the constitutions are nmr data of 7, 8 and the independent synthesis of one compound 8.A reaction mechanism with 1,4-dithiine intermediates is discussed. Key words: Alkyl-1,2,3,4-tetrahydronaphthalen-1-ones; alkyl-5,6,7,8-tetrahydrodinaphthothiophenes; alkyldinaphthothiophenes; dehydrogenation with o-chlorobenzoquinone.
Modern Friedel-Crafts chemistry XIII. Intra- and intermolecular cyclization of some carbonyl derivatives under Friedel-Crafts conditions
Khalaf, Ali A.,Abdel-Wahab, Aboel-Magd A.,El-Khawaga, Ahmed M.,El-Zohry, Maher F.
, p. 285 - 291 (2007/10/02)
Carbonyl group deactivation in the cycloalkylation of aryl haloalkyl ketones was studied.Ketones 1-5 were prepared and subjected to treatment with AlCl3, AlCl3/H2SO4 and H2SO4 catalysts.Whereas AlCl3 catalyst gave no cyclization products, the use of AlCl3/H2SO4 and H2SO4 catalysts afforded the corresponding indanones and/or tetralones (6-11).The intermediate p-methylacrylophenone (12) was also obtained in the case of ketone 2.Furthermore intermolecular cyclizations of benzene, toluene and p-xylene with 3-chloropropionyl chloride (13) and 4-chlorobutyryl chloride (14) were investigated.In the presence of AlCl3/CH3NO2 catalyst, only the corresponding aryl haloalkyl ketones (1-5) were formed whereas the use of AlCl3 catalyst gave, in addition, some cyclic ketones.However, the use of AlCl3/H2SO4 catalyst gave only the corresponding cyclic ketones (6-11).Results are discussed and mechanisms are suggested.In conclusion, carbonyl group deactivation for ring closure is demonstrated in the investigated ketones and cyclization can only effected under strenuous conditions.