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Patrick S. Mariano - One of the best experts on this subject based on the ideXlab platform.
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pyridinium salt photochemistry in a concise route for synthesis of the trehazolin aminocyclitol trehazolamine
Journal of Organic Chemistry, 2005Co-Authors: Xiaohua Feng, Eileen N Duesler, Patrick S. MarianoAbstract:[reaction: see text] A strategy for the concise synthesis of trehazolamine, the aminocyclitol core of the potent trehalase inhibitor trehazolin, has been developed. The methodology takes advantage of photocyclization reaction of 1-methoxyethoxymethyl-3-pivaloxymethylpyridinium perchlorate to generate a bicyclic-aziridine intermediate, which is transformed under aziridine ring opening conditions to the key intermediate, 3,5-diacetoxy-3-pivaloxymethyl-4-(N-acetylamino)Cyclopentene. In addition, the strategy is used in an enantio-divergent sequence for preparation of the natural (+)-trehazolamine and its unnatural (-)-enantiomer. In this route, the chiral auxiliary containing 1-(tetracetyl-alpha-D-glucosyl)-3-pivaloxymethylpyridinium perchlorate undergoes photocyclization to generate separable, diastereomeric bicyclic-aziridines, which are then independently transformed to enantiomeric 3,5-diacetoxy-3-pivaloxymethyl-4-(N-acetylamino)Cyclopentenes.
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exploratory investigations probing a preparatively versatile pyridinium salt photoelectrocyclization solvolytic aziridine ring opening sequence
Journal of Organic Chemistry, 1996Co-Authors: Rong Ling, Mutsuo Yoshida, Patrick S. MarianoAbstract:A novel pyridinium salt photoelectrocyclization−nucleophilic bicyclic aziridine ring opening reaction sequence has been investigated in order to determine its preparative potential. N-Alkylpyridinium perchlorates were found to undergo photoinduced electrocyclization upon irradiation in nucleophilic solvents, such as H2O and MeOH, to efficiently produce 6-alkyl-6-azabicyclo[3.1.0]hex-2-en-4-yl alcohols and ethers. The bicyclic aziridine photoproducts react with a number of different nucleophiles (e.g., H2O, MeOH, AcOH, AcSH) under acid-catalyzed conditions to produce 5-(nucleophile-substituted)-4-(alkylamino)cyclopenten-3-yl alcohols and ethers. The aziridine ring opening processes are both regioselective and stereoselective, yielding trans,trans-trisubstituted Cyclopentenes exclusively, apparently as a consequence of the operation of an SN2 mechanism. The effects of C-alkyl substitution on the regiochemistry of the pyridinium cation photocyclization reaction were briefly probed, and a method was developed...
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Exploratory Investigations Probing a Preparatively Versatile, Pyridinium Salt Photoelectrocyclization−Solvolytic Aziridine Ring Opening Sequence
Journal of Organic Chemistry, 1996Co-Authors: Rong Ling, Mutsuo Yoshida, Patrick S. MarianoAbstract:A novel pyridinium salt photoelectrocyclization−nucleophilic bicyclic aziridine ring opening reaction sequence has been investigated in order to determine its preparative potential. N-Alkylpyridinium perchlorates were found to undergo photoinduced electrocyclization upon irradiation in nucleophilic solvents, such as H2O and MeOH, to efficiently produce 6-alkyl-6-azabicyclo[3.1.0]hex-2-en-4-yl alcohols and ethers. The bicyclic aziridine photoproducts react with a number of different nucleophiles (e.g., H2O, MeOH, AcOH, AcSH) under acid-catalyzed conditions to produce 5-(nucleophile-substituted)-4-(alkylamino)cyclopenten-3-yl alcohols and ethers. The aziridine ring opening processes are both regioselective and stereoselective, yielding trans,trans-trisubstituted Cyclopentenes exclusively, apparently as a consequence of the operation of an SN2 mechanism. The effects of C-alkyl substitution on the regiochemistry of the pyridinium cation photocyclization reaction were briefly probed, and a method was developed...
Rong Ling - One of the best experts on this subject based on the ideXlab platform.
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exploratory investigations probing a preparatively versatile pyridinium salt photoelectrocyclization solvolytic aziridine ring opening sequence
Journal of Organic Chemistry, 1996Co-Authors: Rong Ling, Mutsuo Yoshida, Patrick S. MarianoAbstract:A novel pyridinium salt photoelectrocyclization−nucleophilic bicyclic aziridine ring opening reaction sequence has been investigated in order to determine its preparative potential. N-Alkylpyridinium perchlorates were found to undergo photoinduced electrocyclization upon irradiation in nucleophilic solvents, such as H2O and MeOH, to efficiently produce 6-alkyl-6-azabicyclo[3.1.0]hex-2-en-4-yl alcohols and ethers. The bicyclic aziridine photoproducts react with a number of different nucleophiles (e.g., H2O, MeOH, AcOH, AcSH) under acid-catalyzed conditions to produce 5-(nucleophile-substituted)-4-(alkylamino)cyclopenten-3-yl alcohols and ethers. The aziridine ring opening processes are both regioselective and stereoselective, yielding trans,trans-trisubstituted Cyclopentenes exclusively, apparently as a consequence of the operation of an SN2 mechanism. The effects of C-alkyl substitution on the regiochemistry of the pyridinium cation photocyclization reaction were briefly probed, and a method was developed...
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Exploratory Investigations Probing a Preparatively Versatile, Pyridinium Salt Photoelectrocyclization−Solvolytic Aziridine Ring Opening Sequence
Journal of Organic Chemistry, 1996Co-Authors: Rong Ling, Mutsuo Yoshida, Patrick S. MarianoAbstract:A novel pyridinium salt photoelectrocyclization−nucleophilic bicyclic aziridine ring opening reaction sequence has been investigated in order to determine its preparative potential. N-Alkylpyridinium perchlorates were found to undergo photoinduced electrocyclization upon irradiation in nucleophilic solvents, such as H2O and MeOH, to efficiently produce 6-alkyl-6-azabicyclo[3.1.0]hex-2-en-4-yl alcohols and ethers. The bicyclic aziridine photoproducts react with a number of different nucleophiles (e.g., H2O, MeOH, AcOH, AcSH) under acid-catalyzed conditions to produce 5-(nucleophile-substituted)-4-(alkylamino)cyclopenten-3-yl alcohols and ethers. The aziridine ring opening processes are both regioselective and stereoselective, yielding trans,trans-trisubstituted Cyclopentenes exclusively, apparently as a consequence of the operation of an SN2 mechanism. The effects of C-alkyl substitution on the regiochemistry of the pyridinium cation photocyclization reaction were briefly probed, and a method was developed...
Mutsuo Yoshida - One of the best experts on this subject based on the ideXlab platform.
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exploratory investigations probing a preparatively versatile pyridinium salt photoelectrocyclization solvolytic aziridine ring opening sequence
Journal of Organic Chemistry, 1996Co-Authors: Rong Ling, Mutsuo Yoshida, Patrick S. MarianoAbstract:A novel pyridinium salt photoelectrocyclization−nucleophilic bicyclic aziridine ring opening reaction sequence has been investigated in order to determine its preparative potential. N-Alkylpyridinium perchlorates were found to undergo photoinduced electrocyclization upon irradiation in nucleophilic solvents, such as H2O and MeOH, to efficiently produce 6-alkyl-6-azabicyclo[3.1.0]hex-2-en-4-yl alcohols and ethers. The bicyclic aziridine photoproducts react with a number of different nucleophiles (e.g., H2O, MeOH, AcOH, AcSH) under acid-catalyzed conditions to produce 5-(nucleophile-substituted)-4-(alkylamino)cyclopenten-3-yl alcohols and ethers. The aziridine ring opening processes are both regioselective and stereoselective, yielding trans,trans-trisubstituted Cyclopentenes exclusively, apparently as a consequence of the operation of an SN2 mechanism. The effects of C-alkyl substitution on the regiochemistry of the pyridinium cation photocyclization reaction were briefly probed, and a method was developed...
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Exploratory Investigations Probing a Preparatively Versatile, Pyridinium Salt Photoelectrocyclization−Solvolytic Aziridine Ring Opening Sequence
Journal of Organic Chemistry, 1996Co-Authors: Rong Ling, Mutsuo Yoshida, Patrick S. MarianoAbstract:A novel pyridinium salt photoelectrocyclization−nucleophilic bicyclic aziridine ring opening reaction sequence has been investigated in order to determine its preparative potential. N-Alkylpyridinium perchlorates were found to undergo photoinduced electrocyclization upon irradiation in nucleophilic solvents, such as H2O and MeOH, to efficiently produce 6-alkyl-6-azabicyclo[3.1.0]hex-2-en-4-yl alcohols and ethers. The bicyclic aziridine photoproducts react with a number of different nucleophiles (e.g., H2O, MeOH, AcOH, AcSH) under acid-catalyzed conditions to produce 5-(nucleophile-substituted)-4-(alkylamino)cyclopenten-3-yl alcohols and ethers. The aziridine ring opening processes are both regioselective and stereoselective, yielding trans,trans-trisubstituted Cyclopentenes exclusively, apparently as a consequence of the operation of an SN2 mechanism. The effects of C-alkyl substitution on the regiochemistry of the pyridinium cation photocyclization reaction were briefly probed, and a method was developed...
Igor V. Trushkov - One of the best experts on this subject based on the ideXlab platform.
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Lewis Acid Triggered Vinylcyclopropane–Cyclopentene Rearrangement
Journal of Organic Chemistry, 2017Co-Authors: Olga A Ivanova, Alexey O. Chagarovskiy, Vasiliy D. Krasnobrov, I. I. Levina, Alexey Shumsky, Igor V. TrushkovAbstract:We report a mild Lewis acid induced isomerization of donor–acceptor cyclopropanes, containing an alkenyl moiety and diverse electron-withdrawing group(s) at the adjacent positions, into substituted Cyclopentenes. We have found that 1,1,2-trisubstituted cyclopent-3-enes were exclusively obtained in yield of 51–99% when cyclopropanes with a 2-substituted alkenyl group as a donor underwent isomerization. For cyclopropanes bearing a trisubstituted alkenyl group either the corresponding cyclopent-3-enes or isomeric cyclopent-2-enes having two acceptor groups at the C(1) atom were formed, with the reaction selectivity being determined by the applied Lewis acid. We have shown that the reactivity of the donor–acceptor cyclopropane increases with the increase of the electron-donating character of (hetero)aromatic group attached to the alkenyl moiety. The synthetic utility of the developed methodology was also demonstrated through the synthesis of polysubstituted cyclopentane and piperidine derivatives.
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lewis acid triggered vinylcyclopropane Cyclopentene rearrangement
Journal of Organic Chemistry, 2017Co-Authors: Olga A Ivanova, Alexey O. Chagarovskiy, Vasiliy D. Krasnobrov, I. I. Levina, Alexey Shumsky, Igor V. TrushkovAbstract:We report a mild Lewis acid induced isomerization of donor–acceptor cyclopropanes, containing an alkenyl moiety and diverse electron-withdrawing group(s) at the adjacent positions, into substituted Cyclopentenes. We have found that 1,1,2-trisubstituted cyclopent-3-enes were exclusively obtained in yield of 51–99% when cyclopropanes with a 2-substituted alkenyl group as a donor underwent isomerization. For cyclopropanes bearing a trisubstituted alkenyl group either the corresponding cyclopent-3-enes or isomeric cyclopent-2-enes having two acceptor groups at the C(1) atom were formed, with the reaction selectivity being determined by the applied Lewis acid. We have shown that the reactivity of the donor–acceptor cyclopropane increases with the increase of the electron-donating character of (hetero)aromatic group attached to the alkenyl moiety. The synthetic utility of the developed methodology was also demonstrated through the synthesis of polysubstituted cyclopentane and piperidine derivatives.
Jonathan M Withey - One of the best experts on this subject based on the ideXlab platform.
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preparation of methyl 1r 2s 5s and 1s 2r 5r 2 amino 5 tert butyl cyclopentane 1 carboxylates by parallel kinetic resolution of methyl rs 5 tert butyl Cyclopentene 1 carboxylate
Chemical Communications, 2003Co-Authors: Stephen G Davies, Marcus J. C. Long, Mohamed El M Hammouni, Christopher A Garner, Rachel M Morrison, Miles J Sweet, Narciso M. Garrido, Andrew D. Smith, David Díez, Jonathan M WitheyAbstract:Comparison of the kinetic and parallel kinetic resolutions of methyl (RS)-5-tert-butyl-Cyclopentene-1-carboxylate allows for the efficient synthesis of both (1R,2S,5S)- and (1S,2R,5R)-enantiomers of methyl 2-amino-5-tert-butyl-cyclopentane-1-carboxylate.
