Diastereocontrolled Electrophilic Fluorinations of 2-Deoxyribonolactone: Syntheses of All Corresponding 2-Deoxy-2-fluorolactones and 2′-Deoxy-2′-fluoro-NAD+s
摘要:
Methods to construct 2'-deoxy-2'-fluoro nucleosides have undergone limited improvement in the last 20 years in spite of the substantially increased value of these compounds as pharmaceuticals and as tools for studying biological processes. We herein describe a consolidated approach to synthesize precursors to these commercially and scientifically valuable compounds via diastereocontrolled fluorination of the readily available precursor 2-deoxy-D-ribonolactone. With employment of appropriate sterically bulky silyl protecting groups at the 3 and 5 positions, controlled electrophilic fluorination of the Li-ribonolactone enolate by N-fluorodibenzenesulfonamide yielded the corresponding 2-deoxy-2-fluoroarabinolactone in high isolated yield (72%) The protected 2-deoxy-2,2-difluororibonolactone was obtained similarly in high yield from a second round of electrophilic fluorination (two steps, 51% from protected ribonolactone starting material). Accomplishment of the difficult ribofluorination of the lactone was achieved by the directive effects of a diastereoselectively installed (x-trimethylsilyl group. Electrophilic fluorination of a protected 2-deoxy-2-trimethylsilylarabinolactone via enolate generation provided the protected 2-deoxy-2-fluororibolactone as the exclusive fluorinated product. The reaction also yielded the starting material, the desilylated protected 2-deoxyribonolactone, which was recycled to provide a 38% chemical yield of the fluorinated product (versus initial protected ribonolactone),after consecutive silylation and fluorination cycles. Using our fluorinated sugar precursors, we prepared the 2'-fluoroarabino-, 2'-fluororibo-, and 2',2'-difluoronicotinamide adenine dinucleotides (NAD(+)) of potential biological interest. These syntheses provide the most consolidated and efficient methods for production of sugar precursors of 2'-deoxy-2'-fluoronucleosides and have the advantage of utilizing an air-stable electrophilic fluorinating agent. The fluorinated NAD(+)s are anticipated to be useful for studying a variety of cellular metabolic and signaling processes.
Pyridine coenzyme analogs. 3. Synthesis of three NAD+ analogs containing a 2'-deoxy-2'-substituted nicotinamide arabinofuranosyl moiety
摘要:
A general method for the preparation of 2'-deoxy-2'-substituted arabino-nicotinamide-adenine dinucleotide (NAD) analogues is described. Starting from 1,2:5,6-di-O-isopropylidine-alpha-D-allofuranose, the 2'-amino-, 2'-azido-, and 2'-fluoro-arabino-NAD analogues have been prepared. We report an improved phosphorylation procedure for nicotinamide nucleosides using pyrophosphoryl chloride in m-cresol. The selective reduction of azido substituents by aqueous dithiothreitol (DTT) in the presence of the readily reducible nicotinamide moiety is also reported. With both the 2'-azido and the 2'-fluoro substituents the cis configuration predominates for the incoming nicotinamide, thus allowing the stereoselective formation of the beta anomer in high yield.
Studies on the Synthesis of Nicotinamide Nucleoside and Nucleotide Analogues and Their Inhibitions towards CD38 NADase
作者:Liangren Zhang、Anna Ka Yee Kwong、Zhenjun Yang、Zhe Chen、Hon Cheung Lee、Lihe Zhang
DOI:10.3987/com-11-12361
日期:——
Nicotinamide adenine dinucleotide (NAD) analogues inhibit the NADase activity of CD38. In the current study, efficient protocols for the synthesis of substituted-nicotinamide nucleosides and nucleotides were developed. The one-pot phosphorylation esterification strategy provides a convenient way of obtaining nicotinamide nucleoside phosphodiesters from the corresponding nucleosides. Structure activity relationship information revealed that replacement of 3'-hydroxy group with F or N-3 led to the considerably decrease of activity as compared with ara-F NMN. Phosphodiesterification of nicotinamide nucleosides lowers their inhibitory activities in some extent.
Pyridine coenzyme analogs. 3. Synthesis of three NAD+ analogs containing a 2'-deoxy-2'-substituted nicotinamide arabinofuranosyl moiety
作者:Paul R. Sleath、Anthony L. Handlon、Norman J. Oppenheimer
DOI:10.1021/jo00011a029
日期:1991.5
A general method for the preparation of 2'-deoxy-2'-substituted arabino-nicotinamide-adenine dinucleotide (NAD) analogues is described. Starting from 1,2:5,6-di-O-isopropylidine-alpha-D-allofuranose, the 2'-amino-, 2'-azido-, and 2'-fluoro-arabino-NAD analogues have been prepared. We report an improved phosphorylation procedure for nicotinamide nucleosides using pyrophosphoryl chloride in m-cresol. The selective reduction of azido substituents by aqueous dithiothreitol (DTT) in the presence of the readily reducible nicotinamide moiety is also reported. With both the 2'-azido and the 2'-fluoro substituents the cis configuration predominates for the incoming nicotinamide, thus allowing the stereoselective formation of the beta anomer in high yield.
Diastereocontrolled Electrophilic Fluorinations of 2-Deoxyribonolactone: Syntheses of All Corresponding 2-Deoxy-2-fluorolactones and 2′-Deoxy-2′-fluoro-NAD<sup>+</sup>s
作者:Yana Cen、Anthony A. Sauve
DOI:10.1021/jo900637f
日期:2009.8.21
Methods to construct 2'-deoxy-2'-fluoro nucleosides have undergone limited improvement in the last 20 years in spite of the substantially increased value of these compounds as pharmaceuticals and as tools for studying biological processes. We herein describe a consolidated approach to synthesize precursors to these commercially and scientifically valuable compounds via diastereocontrolled fluorination of the readily available precursor 2-deoxy-D-ribonolactone. With employment of appropriate sterically bulky silyl protecting groups at the 3 and 5 positions, controlled electrophilic fluorination of the Li-ribonolactone enolate by N-fluorodibenzenesulfonamide yielded the corresponding 2-deoxy-2-fluoroarabinolactone in high isolated yield (72%) The protected 2-deoxy-2,2-difluororibonolactone was obtained similarly in high yield from a second round of electrophilic fluorination (two steps, 51% from protected ribonolactone starting material). Accomplishment of the difficult ribofluorination of the lactone was achieved by the directive effects of a diastereoselectively installed (x-trimethylsilyl group. Electrophilic fluorination of a protected 2-deoxy-2-trimethylsilylarabinolactone via enolate generation provided the protected 2-deoxy-2-fluororibolactone as the exclusive fluorinated product. The reaction also yielded the starting material, the desilylated protected 2-deoxyribonolactone, which was recycled to provide a 38% chemical yield of the fluorinated product (versus initial protected ribonolactone),after consecutive silylation and fluorination cycles. Using our fluorinated sugar precursors, we prepared the 2'-fluoroarabino-, 2'-fluororibo-, and 2',2'-difluoronicotinamide adenine dinucleotides (NAD(+)) of potential biological interest. These syntheses provide the most consolidated and efficient methods for production of sugar precursors of 2'-deoxy-2'-fluoronucleosides and have the advantage of utilizing an air-stable electrophilic fluorinating agent. The fluorinated NAD(+)s are anticipated to be useful for studying a variety of cellular metabolic and signaling processes.