Hideyuki Sugimura

Coupling reaction of 1-thiopentofuranosides with silylated pyrimidine bases by activation with N-bromosuccinimide: synthesis of 3′-azido-3′-deoxythymidine and its related nucleoside analogs

Abstract 3′-Azido-3′-deoxythymidine, 3′-fluoro-3′-deoxythymidine, and their 2′- c -substituted derivatives and L-enantiomers were synthesized by the coupling reaction of the corresponding phenyl 1-thiopentofuranosides with silylated thymine by activation with N -bromosuccinimide.

A formation of optically active oxetanes from sugars by Boron trifluoride catalyzed [2+2]cycloaddition reaction

Boron trifluoride etherate catalyzed the formal [2+2]cycloaddition of 2,3-O-isopropylidene derivatives of with enol ethers, vinyl sulfide, and disubstituted terminal olefins to afford chiral oxetanes.

Stereocontrolled synthesis of pyrimidine 2′,3′-dideoxy-β-nucleosides by intramolecular glycosylation

Abstract β-2′,3′-Dideoxynucleosides and their 3′-azido and 3t-fluoro substituted derivatives were synthesized in a stereocontrolled manner by the dimethyl(methylthio)sulfonium tetrafluoroborate promoted intramolecular glycosylation of phenyl 2,3-dideoxy-5-O-(2-pyrimidyl)-1-thioglycosides followed by hydrolysis or ammonolysis.

Structural elucidation of the cyclic products formed by the reaction of 2,3--isopropylidene derivatives of -aldose with allylsilanes, vinyl ethers, or vinyl sulfides in the presence of boron trifluoride etherate

Abstract The structural elucidation of the cyclic products derived from 2,3- O -isopropylidene derivatives of aldehydo -aldose and allylsilanes, vinyl ethers, or vinyl sulfides indicated that tetrahydrofuran derivatives were formed by cyclization accompanied with migration of the isopropylidene group.

β-Selective synthesis of 2'-deoxynucleosides by the coupling of 2-deoxy-1-thio-D-threo-pentofuranosides with silylated thymine

The coupling of the 3,5-O-isopropylidene derivative of phenyl 2-deoxy-1-thio-D-threo-pentofuranoside with silylated thymine in the presence of N-bromosuccinimide yielded 1-(2-deoxy-β-D-threo-pentofuranosyl)thymine with highly anomeric selectivity.

SYNTHESIS OF 3-AZIDO- AND 3-FLUORO-2,3-DIDEOXY-1-THIO-D-ERYTHRO-PENTOFURANOSIDES AND THEIR 2-C-SUBSTITUTED DERIVATIVES

Abstract Phenyl 3-azido- and 3-fluoro-2,3-dideoxy-1-thio-α-D- erythro -pentofuranosides and their 2- C -substituted derivatives, promising precursors of potent antiviral nucleosides, have been synthesized from L-arabinose. A novel synthetic route has been developed for the synthesis of 2,3-dideoxy-2,3-disubstituted-1-thiopentofuranosides as outlined above.

Stereocontrolled Synthesis of Pyridazine, Pyrazine, and Triazine 2′-DEOXY-β-Nucleosides by Means of Intramolecular Glycosylation

Abstract The stereocontrolled synthesis of 2′-deoxynucleoside analogs was explored by intramolecular glycosylation of pyridazine, pyrazines and triazines. These heterocycles were temporarily connected to the 5-O position in 1-thioglycoside via ethereal linkage.

Unusual [2+2]cycloaddition reaction of allylsilanes with 2,3-O-isopropylidene derivatives of aldehyde-aldose catalyzed by boron trifluoride etherate

Abstract In the reaction of allylsilanes with 2,3- O -isopropylidene derivatives of aldehyde -aldose, [2+2] cycloaddition occurred predominantly rather than allylation in the presence of boron trifluoride etherate to give oxetane derivatives as major products together with small amounts of homoallyl alcohols.

Stereoselective formation of tetrahydrofuran rings via [3 + 2] annulation: total synthesis of Plakortone L.

The [3 + 2] annulation of 2,3-O-isopropylidene-aldehydo-aldose with methallyl ether leads to the stereoselective formation of a substituted tetrahydrofuran system, which is converted to a bicyclic lactone derivative via consecutive deprotection, oxidative cleavage of the terminal diol, oxidation of the resulting lactol, and Barton-McCombie deoxygenation. The efficiency of this process was demonstrated by the first total synthesis of Plakortone L.

Facile synthesis of 2′,3′-unsaturated nucleosides from 2-deoxyribose

Abstract A straightforward approach for the synthesis of 2′,3′-unsaturated nucleosides starting from 2-deoxyribose is described. This novel route involves two new methods; (1) preparation of 2-deoxy-1-thioribofuranoside by direct condensation of 2-deoxyribose and thiophenol, (2) formation of the nucleoside skeleton by the direct coupling of 2,3-unsaturated 1-thiopentofuranoside with pyrimidine bases.