• T R Kasturi

      Articles written in Journal of Chemical Sciences

    • Reactions of tetrahalogeno-o-benzoquinones—Part VII. Reaction of alkyl-2-naphthols with tetrachloro-o-benzoquinone

      T R Kasturi R Sivaramakrishnan

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      Reaction of 8-methyl-2-naphthol (4a) with the quinone3 gave a mixture of 8-methyl-2,2-(tetrachloro-o-phenylenedioxy)naphthalen-1(2H)-one (1b) and 8-methyl-1,1-(tetrachloro-o-phenylenedioxy)naphthalen-2(1H)-one (2b) in almost equal amounts. Similarly, reaction of the naphthols (4b), (4d) and (4e) with3 gave the corresponding dienones (1c &2c), (1e &2e) and (1f &2f) in almost equal amounts. Reaction of 8-t-butyl-2-naphthol (4c) with3 gave exclusively 8-t-butyl-2,2-(tetrachloro-o-phenylenedioxy)-naphthalen-1(2H)-one (1d). Oxidation of 3-t-butyl-2-naphthol (4f) with3 gave a mixture of 3-t-butyl-2,2-(tetrachloro-o-phenylendioxy) nephthalene-1(2H)-one(1g) and 3-t-butyl-1,1-(tetrachloro-o-phenylenedioxy)naphthelen-2 (1H)-one (2g) in the ratio 1∶6. Thus, onlyt-butyl group exherts pronounced steric influence on the rearrangement observed in the reaction of β-naphthol with the quinone3. Structures of all the compounds have been established by spectral data.

    • A total synthesis of 4-cyano-1,3-dimethoxy-2-azaestra-1,3,5(10)-trien-17β-ol and its configuration assignment

      T R Kasturi Lalitha Krishnan

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      A total synthesis of 4-cyano-1,3-dimethoxy-2-azaestra-1,3,5(10)-trien-17β-ol(6a) has been achieved starting from 4-cyano-1,3-dimethoxy-5,6,7,8-tetrahydroisoquinoline(1a). Dichromate oxidation of1a gave the 8-oxo derivative(1c) whose structure was confirmed unambiguously by the lanthanide induced chemical shift method. Grignard reaction of1c with vinyl magnesium bromide followed by condensation of the vinyl-alcohol with 2-methyl-cyclopentane-1,3-dione resulted in the seco-dione(2) in 50% yield, which was cyclised withp-toluene sulfonic acid to the pentaenone(3a). Sodium borohydride reduction of3a, stereoselective partial hydrogenation of the 14,15-double bond in3b followed by isomerisation of the 8,9-double bond in4 to 9,11-position and catalytic reduction of the 9,11-double bond gave the title compound(6a). The 14α, 8β, 9α-configuration in6 was tentatively assigned on the basis of its NMR spectrum. The CMR spectra of the steroidal derivative and also the tetrahydroisoquinoline derivative(1b) have been studied and the configuration assigned to the steroid has also been supported by this study.

    • On the mechanism of chiral aldol cyclization reaction

      A Sarkar H R Y Jois T R Kasturi D Dasgupta

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      Spectroscopic studies (1H and13Cnmr, fluorescence anduv) of 2-[3-(p-methoxyphenyl)-3-ketopropyl]-2-methyl-cyclopentane-1, 3-dione in the presence ofl-amino acids andl-N-acetylphenylalanine ethyl ester indicated the possible involvement of a molecular association complex in the transition state of the amino acid catalyzed chiral aldolization of prochiral triketones to yield useful steroidal intermediates.

    • A new synthesis of (±) and (+)-2, 6, 7, 7a-tetrahydro-1β-hydroxy-4-formyl-7aβ-methylindenes

      R Saibaba D K Banerjee T R Kasturi J Mukherjee

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      A new method for the preparation of the synthon (±)-2,6,7,7a-tetrahydro-1β-hydroxy-4-formyl-7aβ-methylindene (1,a) for the total synthesis of steroids in both (±) and (+) forms, starting from the known β-ketoester, (±)-methyl 1β-t-butoxy-5,6,7,7a-tetrahydro-7aβ-methyl-5-keto-4-indancarboxylate (2,a) has been described. An alternative route to (1,a) has been investigated. Although the compound, (±)-1β-hydroxy-5,6,7,7a-tetrahydro-7aβ-methyl-5-keto-4-methoxymethylindan (2,b) could not be prepared, interesting pathways leading to two unexpected products, (±)-5,6,7,7a-tetrahydro-4,7a-dimethyl-5H-indene-1,5-dione and (±)-2,6-diketo-3-methyltricyclo-(5,2,1,0)decan-8-ol (3 and 4), were encountered during an attempted annelation reaction of the ketone, N-diethylamino-5-methoxypentan-3-one (6), with 2-methylcyclopentan-1,3-dione (5). Trapping of the intermediate, (±)-3a,4,5,6,7,7a-hexahydro-3a-hydroxy-4-methylene-7a-methylindene-1,5-dione (7), through the formation of the adduct, (±)-3a,4,5,6,7,7a-hexahydro-3a-hydroxy-4-(1′, 3′-diketo-2′-methylcyclopentano-2′-methylene)-7a-methylindene-1,5-dione (8), established the mechanism of the formation of the products (3 and 4).

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