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Mysore S. Shashidhar - One of the best experts on this subject based on the ideXlab platform.
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orthogonally protected cyclohexanehexols by a one reaction one product approach efficient access to cyclitols and their analogs
European Journal of Organic Chemistry, 2010Co-Authors: Mysore S. Shashidhar, Rajendra C. JagdhaneAbstract:Differentially protected myo-inositol derivatives were prepared from commercially available myo-inositol through regioselective O-alkylation reactions, which give a single product in each step. These derivatives were converted into six isomeric inositol derivatives carrying orthogonal hydroxy protecting groups. For all these reactions, conditions were chosen to prevent the formation of isomeric products, which obviates the need for separation of isomers and provides the required cyclitol derivative in very good yields. The synthetic potential of these derivatives was illustrated by the conversion of some of the orthogonally protected inositol derivatives into other cyclitol derivatives. Isomeric Inositols were also prepared by the global deprotection of all the hydroxy groups.
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intramolecular hydrogen abstraction in radicals derived from inositol 1 3 acetals efficient access to cyclitols
European Journal of Organic Chemistry, 2010Co-Authors: Chebrolu Murali, Bharat P Gurale, Mysore S. ShashidharAbstract:The benzylidene acetals obtained by cleavage of the orthobenzoate moiety in myo-inositol 1,3,5-orthobenzoate were used to prepare mono- as well as di-deoxy inositol derivatives via their xanthates. The dideoxygenation is a result of intramolecular abstraction of the benzylidene acetal hydrogen and subsequent cleavage of the acetal ring. Such a cleavage does not take place in analogous acetals derived from other orthoesters. The 1,3-acetals derived from myo-inositol 1,3,5-orthoesters were also used to prepare neo-inositol and isomeric deoxy-amino Inositols. Most of the reactions in these synthetic sequences starting from myo-inositol give one product in each step. The results presented here show that myo-inositol 1,3,5-orthobenzoate offers many advantages over other orthoesters for the synthesis of cyclitol derivatives from myo-inositol.
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Sulfonate protecting groups. Synthesis of O- and C-methylated Inositols: d- and l-ononitol, d- and l-laminitol, mytilitol and scyllo -inositol methyl ether
Tetrahedron, 2005Co-Authors: Manash P. Sarmah, Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M BhadbhadeAbstract:Abstract Syntheses of d - and l -ononitol, d - and l -laminitol, mytilitol and scyllo-inositol methyl ether starting from myo-inositol are described. One or two of the myo-inositol 1,3,5-orthoformate hydroxyl groups were protected as tosylates. These mono or ditosylates served as key intermediates for the preparation of O- and C-methyl Inositols. Racemic 2,4-di-O-tosyl-myo-inositol 1,3,5-orthoformate was resolved as its diastereomeric camphanates. Use of sulfonate groups for the protection of inositol hydroxyl groups resulted in substantial improvement in the overall yield of O- and C-methyl Inositols.
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sulfonate protecting groups synthesis of d and l myo inositol 1 3 4 5 tetrakisphosphate precursors by a novel silver i oxide mediated o alkylation of 2 4 6 di o acyl 6 4 o sulfonyl myo inositol 1 3 5 orthoformate derivatives through intramolecular as
European Journal of Organic Chemistry, 2003Co-Authors: Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M BhadbhadeAbstract:Alkylation of racemic 2,4-di-O-acyl-6-O-sulfonyl-myo-inositol 1,3,5-orthoformates mediated by silver(I) oxide affords the corresponding racemic 2,4-di-O-alkyl-6-O-sulfonyl-myo-inositol 1,3,5-orthoformates in good yields. Control experiments suggest that these unusual reactions are due to intramolecular assistance by the sulfonyl group. O-Alkylation reactions of myo-inositol 1,3,5-orthoformate derivatives provide a new route for the synthesis of important ether derivatives of myo-inositol, which are intermediates for the preparation of phosphoInositols. The utility of this method is demonstrated by the preparation of D- and L-2,4-di-O-benzyl-myo-Inositols, which were obtained by benzylation of 2,4-di-O-benzoyl-6-O-camphorsulfonyl-myo-inositol 1,3,5-orthoformate and 2,6-di-O-benzoyl-4-O-camphorsulfonyl-myo-inositol 1,3,5-orthoformate. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Kana M. Sureshan - One of the best experts on this subject based on the ideXlab platform.
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Regioselective SN2 reactions for rapid syntheses of azido-Inositols by one-pot sequence-specific nucleophilysis.
Chemical communications (Cambridge England), 2017Co-Authors: Arthi Ravi, Syed Zahid Hassan, Ajithkumar N. Vanikrishna, Kana M. SureshanAbstract:Triflates of myo-inositol undergo facile solvolysis in DMSO and DMF yielding SN2 products substituted with O-nucleophiles; DMF showed slower kinetics. Axial O-triflate undergoes faster substitution than equatorial O-triflate. By exploiting this difference in kinetics, solvent-tuning and sequence-controlled nucleophilysis, rapid synthesis of three azido-Inositols of myo-configuration from myo-inositol itself has been achieved.
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chemoselective alcoholysis acetolysis of trans ketals over cis ketals and its application in the total synthesis of the cellular second messenger d myo inositol 1 4 5 trisphosphate
Organic and Biomolecular Chemistry, 2013Co-Authors: Adiyala Vidyasagar, Atchutarao Pathigoolla, Kana M. SureshanAbstract:The involvement of natural phosphoInositols in various cellular signalling processes and the use of synthetic inositol derivatives in catalysis, supramolecular chemistry, natural product synthesis etc. gave momentum to myo-inositol chemistry. The presence of six secondary hydroxyl groups necessitates efficient protection–deprotection strategies for the synthesis of inositol derivatives. An important strategy for the initial protection of myo-inositol is the di-ketalization, which gives a mixture of three diketals, each having both cis-fused and trans-fused ketals. It is important to have methodologies either to selectively hydrolyze one of the two ketals or to convert one of the two acid labile ketals to an orthogonal base labile protecting group. By exploiting the difference in strain between trans-ketals and cis-ketals, we developed two operationally simple, high yielding methodologies for the chemoselective hydrolysis/acetolysis of trans-ketals (both isopropylidene and cyclohexylidene) of Inositols, leaving the cis-ketal undisturbed, using cheap and easily preparable H2SO4-silica as the catalyst. Also, terminal ketal moieties of carbohydrates and acyclic polyols could be selectively hydrolyzed/acetolyzed leaving the internal ketals intact. The use of methanol as the solvent leads to chemoselective alcoholysis but the use of DCM and acetic anhydride leads to chemoselective acetolysis. Applying this methodology, a short synthesis of D-myo-inositol-1,4,5-trisphosphate has been achieved.
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total syntheses of cyclitol based natural products from myo inositol brahol and pinpollitol
Tetrahedron, 2009Co-Authors: Kana M. Sureshan, Tomohiro Murakami, Yutaka WatanabeAbstract:Abstract Inositol and their derivatives are important class of biologically active natural products. Among the nine theoretically possible Inositols, six are known to occur in nature. Interestingly one or more methyl ethers of these Inositols have been isolated from plants and these methyl Inositols are presumed to have important functions in plant biology. Brahol and pinpollitol are two naturally occurring methylated Inositols reported to have allo-inositol and chiro-inositol configurations, respectively. Adopting our sulfonate inversion strategies for synthesizing protected chiro- and allo-Inositols from cheaply available myo-inositol in combination with new methods we have achieved the total syntheses of these methylated Inositols. The proposed structure of brahol has been synthesized in six steps from myo-inositol. We have not only disproved the proposed structure of brahol but also established its correct structure. Also, we have efficiently synthesized pinpollitol and its positional isomer from myo-inositol. These works involve several selective protection–deprotection strategies of inositol hydroxyl groups.
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Sulfonate protecting groups. Synthesis of O- and C-methylated Inositols: d- and l-ononitol, d- and l-laminitol, mytilitol and scyllo -inositol methyl ether
Tetrahedron, 2005Co-Authors: Manash P. Sarmah, Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M BhadbhadeAbstract:Abstract Syntheses of d - and l -ononitol, d - and l -laminitol, mytilitol and scyllo-inositol methyl ether starting from myo-inositol are described. One or two of the myo-inositol 1,3,5-orthoformate hydroxyl groups were protected as tosylates. These mono or ditosylates served as key intermediates for the preparation of O- and C-methyl Inositols. Racemic 2,4-di-O-tosyl-myo-inositol 1,3,5-orthoformate was resolved as its diastereomeric camphanates. Use of sulfonate groups for the protection of inositol hydroxyl groups resulted in substantial improvement in the overall yield of O- and C-methyl Inositols.
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sulfonate protecting groups synthesis of d and l myo inositol 1 3 4 5 tetrakisphosphate precursors by a novel silver i oxide mediated o alkylation of 2 4 6 di o acyl 6 4 o sulfonyl myo inositol 1 3 5 orthoformate derivatives through intramolecular as
European Journal of Organic Chemistry, 2003Co-Authors: Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M BhadbhadeAbstract:Alkylation of racemic 2,4-di-O-acyl-6-O-sulfonyl-myo-inositol 1,3,5-orthoformates mediated by silver(I) oxide affords the corresponding racemic 2,4-di-O-alkyl-6-O-sulfonyl-myo-inositol 1,3,5-orthoformates in good yields. Control experiments suggest that these unusual reactions are due to intramolecular assistance by the sulfonyl group. O-Alkylation reactions of myo-inositol 1,3,5-orthoformate derivatives provide a new route for the synthesis of important ether derivatives of myo-inositol, which are intermediates for the preparation of phosphoInositols. The utility of this method is demonstrated by the preparation of D- and L-2,4-di-O-benzyl-myo-Inositols, which were obtained by benzylation of 2,4-di-O-benzoyl-6-O-camphorsulfonyl-myo-inositol 1,3,5-orthoformate and 2,6-di-O-benzoyl-4-O-camphorsulfonyl-myo-inositol 1,3,5-orthoformate. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Mitsuo Komiya - One of the best experts on this subject based on the ideXlab platform.
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syntheses of penta o benzyl myo Inositols o β l arabinosyl 1 2 sn myo inositol o α d galactosyl 1 3 sn myo inositol and o α d galactosyl 1 6 o α d galactosyl 1 3 sn myo inositol
Bulletin of the Chemical Society of Japan, 2000Co-Authors: Shinkiti Koto, Motoko Hirooka, Toyosaku Yoshida, Kazuhiro Takenaka, Chizuru Asai, Toshiki Nagamitsu, Hiroaki Sakuma, Michiyo Sakurai, Shinichi Masuzawa, Mitsuo KomiyaAbstract:Two-step conversions of myo-inositol into (±)-2,3,4,5,6- and 1,3,4,5,6-penta-O-benzyl-myo-Inositols are described. Starting from these monohydroxy derivatives of myo-inositol, O-β-L-arabinopyranosyl-(1 → 2)-sn-myo-inositol from Japanese green tea [SENCHA], Camellia sinensis, and O-α-D-galactopyranosyl-(1 → 3)-sn-myo-inositol (galactinol) as well as its homolog, O-α-D-galactopyranosyl-(1 → 6II)-galactinol, were synthesized by way of the in situ activating glycosylation procedure.
Mohan M Bhadbhade - One of the best experts on this subject based on the ideXlab platform.
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Sulfonate protecting groups. Synthesis of O- and C-methylated Inositols: d- and l-ononitol, d- and l-laminitol, mytilitol and scyllo -inositol methyl ether
Tetrahedron, 2005Co-Authors: Manash P. Sarmah, Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M BhadbhadeAbstract:Abstract Syntheses of d - and l -ononitol, d - and l -laminitol, mytilitol and scyllo-inositol methyl ether starting from myo-inositol are described. One or two of the myo-inositol 1,3,5-orthoformate hydroxyl groups were protected as tosylates. These mono or ditosylates served as key intermediates for the preparation of O- and C-methyl Inositols. Racemic 2,4-di-O-tosyl-myo-inositol 1,3,5-orthoformate was resolved as its diastereomeric camphanates. Use of sulfonate groups for the protection of inositol hydroxyl groups resulted in substantial improvement in the overall yield of O- and C-methyl Inositols.
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sulfonate protecting groups synthesis of d and l myo inositol 1 3 4 5 tetrakisphosphate precursors by a novel silver i oxide mediated o alkylation of 2 4 6 di o acyl 6 4 o sulfonyl myo inositol 1 3 5 orthoformate derivatives through intramolecular as
European Journal of Organic Chemistry, 2003Co-Authors: Kana M. Sureshan, Mysore S. Shashidhar, Rajesh G. Gonnade, Mohan M BhadbhadeAbstract:Alkylation of racemic 2,4-di-O-acyl-6-O-sulfonyl-myo-inositol 1,3,5-orthoformates mediated by silver(I) oxide affords the corresponding racemic 2,4-di-O-alkyl-6-O-sulfonyl-myo-inositol 1,3,5-orthoformates in good yields. Control experiments suggest that these unusual reactions are due to intramolecular assistance by the sulfonyl group. O-Alkylation reactions of myo-inositol 1,3,5-orthoformate derivatives provide a new route for the synthesis of important ether derivatives of myo-inositol, which are intermediates for the preparation of phosphoInositols. The utility of this method is demonstrated by the preparation of D- and L-2,4-di-O-benzyl-myo-Inositols, which were obtained by benzylation of 2,4-di-O-benzoyl-6-O-camphorsulfonyl-myo-inositol 1,3,5-orthoformate and 2,6-di-O-benzoyl-4-O-camphorsulfonyl-myo-inositol 1,3,5-orthoformate. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Shinkiti Koto - One of the best experts on this subject based on the ideXlab platform.
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syntheses of penta o benzyl myo Inositols o β l arabinosyl 1 2 sn myo inositol o α d galactosyl 1 3 sn myo inositol and o α d galactosyl 1 6 o α d galactosyl 1 3 sn myo inositol
Bulletin of the Chemical Society of Japan, 2000Co-Authors: Shinkiti Koto, Motoko Hirooka, Toyosaku Yoshida, Kazuhiro Takenaka, Chizuru Asai, Toshiki Nagamitsu, Hiroaki Sakuma, Michiyo Sakurai, Shinichi Masuzawa, Mitsuo KomiyaAbstract:Two-step conversions of myo-inositol into (±)-2,3,4,5,6- and 1,3,4,5,6-penta-O-benzyl-myo-Inositols are described. Starting from these monohydroxy derivatives of myo-inositol, O-β-L-arabinopyranosyl-(1 → 2)-sn-myo-inositol from Japanese green tea [SENCHA], Camellia sinensis, and O-α-D-galactopyranosyl-(1 → 3)-sn-myo-inositol (galactinol) as well as its homolog, O-α-D-galactopyranosyl-(1 → 6II)-galactinol, were synthesized by way of the in situ activating glycosylation procedure.