Tetralones structures

The clinical effectiveness of oxypertine (89) led eventually to the evaluation of the te-tralone derivative (90)(346).A blending of the indole and tetralone structures of (89) and... 

The aromatization of the oxepin structure can be accompanied by other acid-catalyzed reactions such as the hydrolysis of ketals. Dimethyl 11 -oxo-6-oxabicyclo[5.4.0]undeca-l (7),2,4-triene-2,3-dicarboxylate ethylene ketal reacts in the presence of trifluoroacetic acid to give the tetralone system 3.133... 

RuC1 (CH3CN)3 is made from RuCl with and CH CN it is brick-red. The X-ray crystal structure of RuCljCCHjCbOj.dCHjCN shows a mer-octahedral geometry. The electrochemistry of the complex was stucUed as were IR and mass spectra. As RuCljCCHjCbOj/aq. L CIO )/ electrodes it oxidised tetralin to tetralone [786].. ... 

FIGURE 18 Chemical structures of econazole, miconazole, sulconazole, tetralone derivatives, and aromatase inhibitors. 

Consequently, Dehmlow and coworkers modified the cinchona alkaloid structure to elucidate the role of each ofthe structural motifs of cinchona alkaloid-derived chiral phase-transfer catalysts in asymmetric reactions. Thus, the quinoline nucleus of cinchona alkaloid was replaced with various simple or sterically bulky substituents, and the resulting catalysts were screened in asymmetric reactions (Scheme 7.2). The initial results using catalysts 8-11 in the asymmetric borohydride reduction of pivalophenone, the hydroxylation of 2-ethyl-l-tetralone and the alkylation of SchifF s base each exhibited lower enantiomeric excesses than the corresponding cinchona alkaloid-derived chiral phase-transfer catalysts [14]. 

Solvent and concentration effects on keto-enol tautomerization have been investigated in DMSO-water mixtures and aqueous micellar solutions, for 2-acetylcyclo-hexanone and 2-acetyl-1-tetralone.286 Dramatic rate increases aboves 60% DMSO content have been explained in terms of solvent structure solvent polarity alone cannot rationalize the effect. 

For the structural optimization of the tricyclic triazolium salt 119 the cw-tricyclic lactam 126 was chosen as the precursor for the synthesis of the tetracyclic triazolium salt 127. The diastereo- and enantiopure y-lactam 126 was synthesized following a procedure reported by Ennis et al. (Scheme 32) (Ennis et al. 1996 Nieman and Ennis 2000). a-Tetralone (124) was a-alkylated with ethyl bromoacetate and subsequently hydrolyzed to the corresponding carboxylic acid. Condensation with (R)-phenylglycinol yielded the lactam 125 as a single stereoisomer. Stereoselective reduction, dehydration of the alcohol, and acid-catalyzed enamine hydrolysis provided the cis-tricyclic lactam 126. The one-pot procedure that had previously been successful in the synthe-... 

Enamines derived from cyclohexanone and and a-tetralones react with chloro-(phenyl)carbene [generated from dichloro(phenyl)methane and potassium tert-butoxide] to give either 1-chloro-l-phenyl-substituted cyclopropanes, or other products.The type of products formed depends on the structure of the amine moiety in the starting enamines (Table 7). 

Deduce structures for the heterocyclic products from the following combinations (i) C11H7N3O2 from 2-aminobenzaldehyde and barbituric acid (ii) CmHuNOs from 4,5-methylenedioxy-2-aminobenzaldehyde and dimethyl acetylenedicarboxylate (iii) CmHuNS from 2-aminoacetophenone and 2-acetylthiophen (iv) C21H19NO from 2-aminobenzophenone and dimedone (v) C15H12N2O2S from 2-aminopyridine-3-aldehyde and 1-phenylsulfonylacetone (vi) C15HHN3 from 4-amino-pyrimidine-5-aldehyde and a-tetralone. 

The structure and absolute stereochemistry of hinesol (282) has now been firmly established by an unequivocal synthesis which involved the tricyclic dienone (329) prepared from 6-methoxy-l-tetralone. Treatment of the dienone with lithium dimethylcopper gave a mixture of syn and anti enones (330). By a series of stereoselective reactions this compound was converted to the diol (331) whose mono-mesylate underwent a base-induced cleavage to give the spiro[4,5]-ketone (332). Elaboration of this ketone to hinesol was accomplished along... 

More complex structures can be derived from 1-tetralone through its conversion to (tetrahydro-l-oxo-2-naphthyl)ethanoic acid and subsequent reaction with a heteroaryllithium. Sequential cyclisation to the dibenzofuran or thiophene and propargylation affords fast fading 3,4-dihydronaphtho[2,l-/ [l]benzofuro[2,3-/r]naphtho[l,2-6]pyrans and thiophene analogues <00WOP77007>. 

Baneijee et al.66 have developed an alternative synthesis of the compound (129) whose utility in synthesis of Mansonone F (120) has been reported by Suh and collaborators.65 This is described in Scheme 13. Tetralone (127) was reduced with sodium borohydride to alcohol which on alkylation with benzyl chloride produced benzyl derivative (132). Its conversion to (133) was attempted by treatment with boron tribromide in dichloromethane. C ompound (133) (characterized b y m ass s pectroscopy) was obtained in poor yield. The major product was the diol (134), whose structure was confirmed by spectral data. It indicates that the demethylation was accompanied by debenzylation. Treatment of diol (134) with triethyl orthoformate and aluminium chloride afforded aldehyde (135) which was subjected to catalytic hydrogenation to produce compound (136). It was transformed to ketone (137) by oxidation and then made to react with methylmagnesium bromide in ether. The resulting tertiary alcohol on heating with p-toluenesulfonic acid in toluene for 24 hr produced the naphthalene (129) in 78% yield. 

Over the last seventy years over sixty species of Aristolochia have been exploited for chemical examination by research groups throughout the world and a variety of compounds have been isolated. The spectrum of physiologically-active metabolites from Aristolochia species covers 14 major groups based on structure aristolochic acid derivatives, aporphines, amides, benzylisoquinolines, isoquinolones, chlorophylls, terpenoids, lignans, biphenyl ethers, flavonoids, tetralones, benzenoids, steroids, and miscellaneous. The aristolochic acid derivatives, host of phenanthrene derived metabolites were further classified into aristolochic acids, sodium salts of aristolochic acids, aristolochic acid alkyl esters, sesqui- and diterpenoid esters of aristolochic acids, aristolactams, denitroaristolochic acids, and aristolactones. The terpenoids can further be subdivided into 4 groups mono-, sesqui-, di- and tetraterpenoids. 

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