4 research outputs found
Asymmetric synthesis of spiroacetals : towards the broussonetin H
Le motif spiroacĂ©tal est une structure prĂ©sente dans le squelette de nombreuses molĂ©cules naturelles possĂ©dant des activitĂ©s biologiques variĂ©es et pour laquelle il existe de nombreuses voies de synthĂšse. En revanche, son analogue azotĂ©, le motif spiroaminal a Ă©tĂ© beaucoup moins Ă©tudiĂ©. Le premier de nos objectifs a consistĂ© Ă dĂ©velopper une voie de synthĂšse Ă©nantiosĂ©lective, la plus gĂ©nĂ©rale possible, de ce motif. La stratĂ©gie retenue repose sur une Ă©tape clĂ© de spirocyclisation acido-catalysĂ©e dâaminohydroxycĂ©tones issues de lâalkylation sĂ©quentielle de lâacĂ©tone N,N-dimĂ©thylhydrazone par divers synthons iodĂ©s. Si les spiroaminals attendus nâont pas pu ĂȘtre obtenus, ces cĂ©tones polyfonctionnalisĂ©es ont permis dâaccĂ©der efficacement Ă des spiroacĂ©tals originaux : les 1,6-dioxaspiro [4.6] undĂ©canes et les 1,7-dioxaspiro [5.6] dodĂ©canes. Dans une deuxiĂšme partie de notre travail, nous nous sommes intĂ©ressĂ©s Ă la synthĂšse totale de la broussonĂ©tine H, spiroacĂ©tal naturel possĂ©dant une trĂšs forte activitĂ© inhibitrice vis-Ă -vis de ÎČ-glycosidases. Son Ă©laboration a Ă©tĂ© envisagĂ©e par couplage entre deux fragments clĂ© : le 2-Ă©thynyl-1,7-dioxaspiro [5.5] undĂ©cane et un iminocyclitol porteur dâun Ă©poxyde. La synthĂšse de ces deux composĂ©s a Ă©tĂ© rĂ©alisĂ©e en peu dâĂ©tapes et avec dâexcellents rendements. Leur couplage a permis lâobtention dâun prĂ©curseur directe de la broussonĂ©tine H. LâĂ©tape finale de dĂ©protection reste Ă optimiser afin de permettre lâisolement du produit naturel.Spiroketal pattern appears in the skeleton of many natural products exhibiting various biological activities, and several synthetic routes to it have been reporting. Contrarily, spiroaminal moiety, its nitrogen analogue, has been less studied. The first of our objectives consisted to develop the most general enantioselective synthetic pathway to this framework. The adopted strategy is based on a key step acid-catalysed spirocyclisation of aminohydroxyketones, resulting from the sequential alkylation of acetone N,N-dimethylhydrazone by various iodide derivatives. If targeted spiroaminals could not be obtained, these polyfunctionalized ketones permit an efficient access to original spiroketals skeletons like 1,6-dioxaspiro [4.6] undecanes and 1,7-dioxaspiro [5.6] dodecanes. In a second part, we focused on the total synthesis of broussonetine H, a natural spiroketal possessing powerful inhibitory activities against ÎČ-glycosidases. Its elaboration was envisaged through the coupling between two key fragments : the 2-ethynyl-1,7-dioxaspiro [5.5] undecane and an iminocyclitol substitued by an epoxide. The synthesis of these two compounds was realized in few steps with good overall yelds.Their coupling led to a protected form of broussonetine H. The final deprotection step remains to be optimized to allow the final isolation of the natural product
SynthÚse asymétrique de spiroacétals : vers la broussonétine H
Spiroketal pattern appears in the skeleton of many natural products exhibiting various biological activities, and several synthetic routes to it have been reporting. Contrarily, spiroaminal moiety, its nitrogen analogue, has been less studied. The first of our objectives consisted to develop the most general enantioselective synthetic pathway to this framework. The adopted strategy is based on a key step acid-catalysed spirocyclisation of aminohydroxyketones, resulting from the sequential alkylation of acetone N,N-dimethylhydrazone by various iodide derivatives. If targeted spiroaminals could not be obtained, these polyfunctionalized ketones permit an efficient access to original spiroketals skeletons like 1,6-dioxaspiro [4.6] undecanes and 1,7-dioxaspiro [5.6] dodecanes. In a second part, we focused on the total synthesis of broussonetine H, a natural spiroketal possessing powerful inhibitory activities against ÎČ-glycosidases. Its elaboration was envisaged through the coupling between two key fragments : the 2-ethynyl-1,7-dioxaspiro [5.5] undecane and an iminocyclitol substitued by an epoxide. The synthesis of these two compounds was realized in few steps with good overall yelds.Their coupling led to a protected form of broussonetine H. The final deprotection step remains to be optimized to allow the final isolation of the natural product.Le motif spiroacĂ©tal est une structure prĂ©sente dans le squelette de nombreuses molĂ©cules naturelles possĂ©dant des activitĂ©s biologiques variĂ©es et pour laquelle il existe de nombreuses voies de synthĂšse. En revanche, son analogue azotĂ©, le motif spiroaminal a Ă©tĂ© beaucoup moins Ă©tudiĂ©. Le premier de nos objectifs a consistĂ© Ă dĂ©velopper une voie de synthĂšse Ă©nantiosĂ©lective, la plus gĂ©nĂ©rale possible, de ce motif. La stratĂ©gie retenue repose sur une Ă©tape clĂ© de spirocyclisation acido-catalysĂ©e dâaminohydroxycĂ©tones issues de lâalkylation sĂ©quentielle de lâacĂ©tone N,N-dimĂ©thylhydrazone par divers synthons iodĂ©s. Si les spiroaminals attendus nâont pas pu ĂȘtre obtenus, ces cĂ©tones polyfonctionnalisĂ©es ont permis dâaccĂ©der efficacement Ă des spiroacĂ©tals originaux : les 1,6-dioxaspiro [4.6] undĂ©canes et les 1,7-dioxaspiro [5.6] dodĂ©canes. Dans une deuxiĂšme partie de notre travail, nous nous sommes intĂ©ressĂ©s Ă la synthĂšse totale de la broussonĂ©tine H, spiroacĂ©tal naturel possĂ©dant une trĂšs forte activitĂ© inhibitrice vis-Ă -vis de ÎČ-glycosidases. Son Ă©laboration a Ă©tĂ© envisagĂ©e par couplage entre deux fragments clĂ© : le 2-Ă©thynyl-1,7-dioxaspiro [5.5] undĂ©cane et un iminocyclitol porteur dâun Ă©poxyde. La synthĂšse de ces deux composĂ©s a Ă©tĂ© rĂ©alisĂ©e en peu dâĂ©tapes et avec dâexcellents rendements. Leur couplage a permis lâobtention dâun prĂ©curseur directe de la broussonĂ©tine H. LâĂ©tape finale de dĂ©protection reste Ă optimiser afin de permettre lâisolement du produit naturel
SynthÚse asymétrique de spiroacétals (vers la broussonétine H)
Le motif spiroacĂ©tal est une structure prĂ©sente dans le squelette de nombreuses molĂ©cules naturelles possĂ©dant des activitĂ©s biologiques variĂ©es et pour laquelle il existe de nombreuses voies de synthĂšse. En revanche, son analogue azotĂ©, le motif spiroaminal a Ă©tĂ© beaucoup moins Ă©tudiĂ©. Le premier de nos objectifs a consistĂ© Ă dĂ©velopper une voie de synthĂšse Ă©nantiosĂ©lective, la plus gĂ©nĂ©rale possible, de ce motif. La stratĂ©gie retenue repose sur une Ă©tape clĂ© de spirocyclisation acido-catalysĂ©e d aminohydroxycĂ©tones issues de l alkylation sĂ©quentielle de l acĂ©tone N,N-dimĂ©thylhydrazone par divers synthons iodĂ©s. Si les spiroaminals attendus n ont pas pu ĂȘtre obtenus, ces cĂ©tones polyfonctionnalisĂ©es ont permis d accĂ©der efficacement Ă des spiroacĂ©tals originaux : les 1,6-dioxaspiro [4.6] undĂ©canes et les 1,7-dioxaspiro [5.6] dodĂ©canes. Dans une deuxiĂšme partie de notre travail, nous nous sommes intĂ©ressĂ©s Ă la synthĂšse totale de la broussonĂ©tine H, spiroacĂ©tal naturel possĂ©dant une trĂšs forte activitĂ© inhibitrice vis-Ă -vis de b-glycosidases. Son Ă©laboration a Ă©tĂ© envisagĂ©e par couplage entre deux fragments clĂ© : le 2-Ă©thynyl-1,7-dioxaspiro [5.5] undĂ©cane et un iminocyclitol porteur d un Ă©poxyde. La synthĂšse de ces deux composĂ©s a Ă©tĂ© rĂ©alisĂ©e en peu d Ă©tapes et avec d excellents rendements. Leur couplage a permis l obtention d un prĂ©curseur directe de la broussonĂ©tine H. L Ă©tape finale de dĂ©protection reste Ă optimiser afin de permettre l isolement du produit naturel.Spiroketal pattern appears in the skeleton of many natural products exhibiting various biological activities, and several synthetic routes to it have been reporting. Contrarily, spiroaminal moiety, its nitrogen analogue, has been less studied. The first of our objectives consisted to develop the most general enantioselective synthetic pathway to this framework. The adopted strategy is based on a key step acid-catalysed spirocyclisation of aminohydroxyketones, resulting from the sequential alkylation of acetone N,N-dimethylhydrazone by various iodide derivatives. If targeted spiroaminals could not be obtained, these polyfunctionalized ketones permit an efficient access to original spiroketals skeletons like 1,6-dioxaspiro [4.6] undecanes and 1,7-dioxaspiro [5.6] dodecanes. In a second part, we focused on the total synthesis of broussonetine H, a natural spiroketal possessing powerful inhibitory activities against b-glycosidases. Its elaboration was envisaged through the coupling between two key fragments : the 2-ethynyl-1,7-dioxaspiro [5.5] undecane and an iminocyclitol substitued by an epoxide. The synthesis of these two compounds was realized in few steps with good overall yelds.Their coupling led to a protected form of broussonetine H. The final deprotection step remains to be optimized to allow the final isolation of the natural product.CLERMONT FD-Bib.Ă©lectronique (631139902) / SudocSudocFranceF
Strategies and performance of the CMS silicon tracker alignment during LHC Run 2
The strategies for and the performance of the CMS silicon tracking system alignment during the 2015â2018 data-taking period of the LHC are described. The alignment procedures during and after data taking are explained. Alignment scenarios are also derived for use in the simulation of the detector response. Systematic effects, related to intrinsic symmetries of the alignment task or to external constraints, are discussed and illustrated for different scenarios