- A SIMPLE SYNTHESIS OF (+/-) 4-DEMETHOXYDAUNOMYCINONE
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A new and simple synthesis of 4-demethoxy-7-deoxydaunomycinone has been carried out essentially in three steps starting from 1,4-dimethoxy-6-tetralone.
- Rao, Rama A. V.,Deshpande, V. H.,Reddy, Laxma N.
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- Synthesis of anthracyclinone precursor: 5,12-dihydroxy-1,3,4- trihydronaphthacene-2,6,11-quinone
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Two practical and efficient approaches for preparing large quantities of 5,12-dihydroxy-1,3,4-trihydronaphthacene-2,6,11-quinone 9 are described. Both synthetic approaches involve a simple route with a fewer number of steps and utilize readily available and inexpensive starting materials. Large-scale production of this precursor may prove to be useful for further research involving the synthesis of antineoplastic anthracyclines and development of their analogs with increased activity and decreased toxicity.
- Tririya, Gasirat,Zanger, Murray
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p. 3047 - 3059
(2007/10/03)
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- Baker's Yeast Mediated Reduction of Aromatic Ring Substituted 2-Tetralones
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2-Tetralones mono- and disubstituted with methoxy or hydroxy groups in the aromatic ring are hydrogenated to 2-tetralols in good yields by non-fermenting baker's yeast.The prevalent enantioform of the reduction product and its e.e. were found to depend on the substitution pattern.In one case, i.e. the biotransformation of 5-methoxy-2-tetralone into the corresponding 2-tetralol, an e.e. >/= 98percent was observed.A simple abstract model for explaining and predicting the stereochemical outcome in the yeast-mediated carbonyl reduction of 2-tetralones is proposed.
- Manitto, Paolo,Speranza, Giovanna,Monti, Diego,Fontana, Gabriele,Panosetti, Elisa
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p. 11531 - 11546
(2007/10/02)
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- Synthesis and adrenergic properties of new duplicated analogs of methoxamine
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New duplicated analogs of the α1-selective agonist methoxamine and of its cyclic derivative 5,8-dimethoxy-1,2,3,4-tetrahydro-2-naphthylamine have been synthesized and tested for their adrenergic properties. All the compounds prepared, presenting a polymethylene spacer of varying length between two units of the active structure, turned out to be completely devoid of any α-stimulating activity. Surprisingly, some of them showed a marked β-adrenergic agonistic effect, being the most interesting compound active at nanomolar concentration.
- Perez,Rosell,Mauleon,Carganico
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p. 1155 - 1166
(2007/10/02)
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- P-aminophenols, derivatives thereof and method of use
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p-Aminophenols are provided having the structure STR1 wherein m is 0, 1 or 2; n is 0, 1, 2 or 3; R1 and R2 may be the same or different and are H, hydroxy or alkoxy; R3 is H, lower alkyl, alkanoyl or aroyl and R4 is H, lower alkyl or alkanoyl, and including acid-addition salts thereof. These compounds are useful as inhibitors of leukotriene production and as such are useful as antiallergy, anti-inflammatory and anti-psoriatic agents.
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- Model Studies for an Asymmetric Synthesis of (+)-4-Demethoxydaunomycinone
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2-Hydroxymethyl-5,8-dimethoxy-3,4-dihydronaphthalene (II) on t-butyl hydroperoxide oxidation followed by LAH reduction gives 2-hydroxy-2-hydroxymethyl-5,8-dimethoxy-1,2,3,4-tetrahydronaphthalene (IVa) in 85percent yield.The corresponding O-benzyl derivate (VI) on PDC oxidation affords 2-benzyloxy-5,8-dimethoxy-1,2,3,4-tetrahydronaphthyl-2-aldehyde (VII), which on Grignard reaction with methylmagnesium iodide followed by PDC oxidation affords the desired (+/-)-2-acetyl-2-O-benzyl-5,8-dimethoxy-1,2,3,4-tetrahydronaphthalene (IXa) in 70percent yield.Friedel-Crafts condensation of IXa with phthalic anhydride in the presence of AlCl3-NaCl melt furnishes (+/-)-4-demethoxy-7-deoxydaunomycinone (Ia) in 74percent yield, which on 7-hydroxylation affords the desired (+/-)-4-demethoxydaunomycinone (Ib) in 40percent yield.
- Mehendale, A. R.,Kulkarni, Alpana,Nagarajan, Geeta
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p. 305 - 307
(2007/10/02)
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- Simple Preparation of β-Tetralones and β-Indanones by a 1,2-Carbonyl Group Transposition
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By a four-step procedure, the ketones 3 are converted into the β-tetralones 7a-d and the β-indanones 7e, f via the intermediates 4, 5, and 6.
- Braun, Manfred,Bernhard, Carlo
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p. 435 - 437
(2007/10/02)
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- 8-Hydroxy-2-(alkylamino)tetralins and related compounds as central 5-hydroxytryptamine receptor agonists
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A series of 2-(alkylamino)tetralins related to 8-hydroxy-2-(di-n-propylamino)tetralin (21) were prepared and tested as dopamine (DA) and 5-hydroxytryptamine (5-HT) receptor agonists. Several of the compounds were potent 5-HT agonists devoid of DA-mimetic effects. N-Ethyl or N-propyl substitution of 8-hydroxy-2-aminotetralin gave the most potent agonists. It was shown that the most potent compound, (+)-21, has the 2R configuration. 5,8-Dimethoxy-2-(di-n-propylamino)tetralin (31) was found to be a weak DA agonist devoid of 5-HT activity. The corresponding indan derivative, 4,7-dimethoxy-2-(di-n-propylamino)indan (39), has been reported to be active on both DA and 5-HT receptors. The 5-HT-stimulating properties of compounds 21 and 39 as compared to the incapability of compound 31 to activate the 5-HT receptor is tentatively explained by the assumed mode of binding of the compounds to the 5-HT receptor.
- Arvidsson,Hacksell,Johansson,Nilsson,Lindberg,Sanchez,Wikstroem,Svensson,Hjorth,Carlsson
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- AN EFFICIENT SYNTHESIS OF OPTICALLY PURE ANTHRACYCLINONE INTERMEDIATES BY THE NOVEL USE OF MICROBIAL REDUCTION
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Reduction of the racemic α-hydroxy ketones((+/-)-3a,b) with fermenting baker's yeast followed by fractional recrystallization and oxidation was found to readily afford optically pure anthracyclinone intermediates((R)(-)-3a,b) and their partially optically active antipodes((S)(+)-3a,b).The useless enantiomers((S)(+)-3a,b) and diastereomeric vicinal-diols((+)-5a,b) could be recycled to (+/-)-3a,b and the achiral ketones(6a,b) by racemization and oxidative cleavage, respectively.
- Terashima, Shiro,Tamoto, Katsumi
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p. 3715 - 3718
(2007/10/02)
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- 5,12-Epoxy-naphthacene-6,11-dione derivatives
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There is provided a novel method of synthesizing certain tetracyclic quinones. In particular, there is provided a novel route to the synthesis of (+)-7-deoxydaunomycinone and analogs thereof which includes the provision of novel tetrahydronaphthoquinones and tetracyclic quinone intermediates. The compounds of the present invention are provided through a route comprising a Diels-Alder addition of certain isobenzofurans to certain novel tetrahydronaphthoquinones. The products of the synthetic route provided herein may be converted into compounds of known antibiotic and antineoplastic activity.
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