Dolatrai M. Vyas

Discovery of a 2,4-disubstituted pyrrolo[1,2-f][1,2,4]triazine inhibitor (BMS-754807) of insulin-like growth factor receptor (IGF-1R) kinase in clinical development.

This report describes the biological activity, characterization, and SAR leading to 9d (BMS-754807) a small molecule IGF-1R kinase inhibitor in clinical development.

Carbon-13 Nuclear Magnetic Resonance Spectra of Some Dendroketose and Other Furanose Derivatives

The carbon-13 n.m.r. spectra of derivatives of the branched-chain sugars apiose and dendroketose, and of other furanose sugars, are reported. The study has permitted assignment of the configuration at the branching carbon atom and at the anomeric center in the dendroketose derivatives.

Synthesis of 5-deoxy-d-xylo-hexose and 5-deoxy-l-arabino-hexose, and their conversion into adenine nucleosides

Abstract Anti -Markovnikov hydration of the olefinic bond of 5,6-dideoxy-1,2- O -isopropylidene-3- O-p -tolylsulfonyl-α- d - xylo -hex-5-enofuranose ( 4 ) and methyl 5,6-dideoxy-2,3-di- O-p -tolylsulfonyl-α- l - arabino -hex-5-enofuranoside ( 11 ) by the addition of iodine trifluoroacetate, followed by hydrogenation in the presence of a Raney nickel catalyst in ethanol containing triethylamine, afforded 5-deoxy-1,2- O -isopropylidene-3- O-p -tolylsulfonyl-α- d - xylo -hexofuranose ( 6 ) and methyl 5-deoxy-2,3-di- O-p -tolylsulfonyl-α- d - arabino -hexofuranoside ( 14 ), respectively. 5-deoxy- d - xylo -hexose and 5-deoxy- l - arabino -hexose were prepared from 6 and 14 , respectively, by photolytic O -detosylation and acid hydrolysis. Syntheses of 9-(5-deoxy-β- d - xylo -hexofuranosyl)-adenine and 9-(5-deoxy-α- l - arabino -hexofuranosyl)adenine are also described. Application of the sodium naphthalene procedure, for O -detosylation, to 11 is reported in connection with an alternative synthetic route to methyl 5-deoxy-α- l - arabino - hexofuranoside.

Carbon-13 nuclear magnetic resonance spectra of carbohydrate oxirane derivatives

Abstract The 13 C-chemical shifts and 1 J C,H values of two series of carbohydrate oxirane derivatives, namely methyl 2,3-anhydro-ribo- and -lyxofuranosides and methyl 2,3-anhydro-4,6- O -benzylidene-manno- and -allopyranosides have been determined. The assignment of 13 C resonances has been established mainly by the examination of the proton-coupled and the selective proton-decoupled spectra. The effect of the oxirane rings on the chemical shifts of β and γ carbon atoms (from the oxirane ring oxygen atom) has been observed. Large 1 J C,H values associated with cis CH bonds adjacent to the oxirane rings relative to those of trans counterparts have been found.

Studies on the synthesis of novel carbohydrates with sulphur in the ring. Part II. Analogues of derivatives of unsaturated deoxy-ulopyranosidonic acids via Diels–Alder reactions with methyl cyanodithioformate

3,6-Dihydro-2-methylthio-2H-thiopyran-2-carbonitrile (5) and its 3-methoxy-derivative (11) were obtained directly from the Diels–Alder reactions of methyl cyanodithioformate (4) with buta-1,3-diene and trans-1-methoxy-buta-1,3-diene, respectively. The regioselectivity of the reagent (4) is opposite to that of carbonyl dienophiles with 1-alkoxybuta-1,3-dienes. The structure of compound (11) was established by 1H n.m.r. studies involving compounds (5) and (11) and their selectively oxidized and/or reduced derivatives. The results indicated that (11) exists predominantly in the 0H2 conformation in chloroform.

Addition of pseudohalogens to unsaturated carbohydrates. VI. Synthesis of 4′ -thiocordycepin

The addition of the pseudohalogen iodine nitrate (IONO2) to the endocyclic alkenic bond in benzyl 2-O-benzyl-3,4-dideoxy-α-D-glycero-pent-3-enopyranoside (3) is described. The stereochemistry and regiochemistry of addition were elucidated by chemical degradation, 1Hmr spectroscopy, mass-spectral analysis, and polarimetry. A synthetic route to 4′-thiocordycepin (20) from compound 3, by way of the intermediacy of the preponderant iodine nitrate adduct of 3, namely, benzyl 2-O-benzyl-3-deoxy-3-iodo-4-O-nitro-β-L-lyxopyranoside (4), is also described.

Synthesis of gem-di-C-substituted derivatives of carbohydrates by way of nucleophilic-addition reactions of aldohexofuranoid 3-C-methylene derivatives

Abstract Nucleophilic Michael-type additions to aldohexofuranoid 3- C -methylene derivatives, namely, 3-deoxy-1,2:5,6-di- O -isopropylidene-3- C -nitromethylene-α- d - ribo -hexofuranose and 3- C -[cyano(ethoxycarbonyl)methylene]-3-deoxy-1,2:5,6-di- O -isopropylidene-α- d - ribo -hexofuranose employing phase-transfer catalysis, afforded novel gem -di- C -substituted sugars. The conversion of 3-deoxy-1,2:5,6-di- O -isopropylidene-3- C -methyl-3- C -nitromethyl-α- d - allo -hexofuranose into a 3- C -hydroxymethyl-3- C -methyl derivative with titanium trichloride, and that of the nitromethyl groups of 3-deoxy-1,2:5,6-di- O -isopropylidene-3,3-di- C -nitromethyl-α- d - ribo -hexofuranose, and 3-deoxy-1,2:5,6-di- O -isopropylidene-3- C -methyl-3- C -nitromethyl- and -3- C -nitromethyl-α- d - allo -hexofuranose into cyano groups with phosphorus trichloride in pyridine is also described.

Carbon-13 nuclear magnetic resonance spectra of acyclic carbohydrate derivatives : alditols, 1,2-bis(phenylhydrazones), and dithioacetals

The carbon-13 n.m.r. spectra of acyclic carbohydrate derivatives, namely alditols. 1,2-bis(phenylhydrazones), dithioacetals, and related acyclic sugar derivatives, are reported. The study has corroborated earlier results, based on 1H n.m.r. investigations, on the conformational behaviour of such compounds in solution. Application of this technique in elucidation of regiospecificity of oxidation of alditols by Acetobacter suboxydans is discussed.

Synthesis of medium heterocyclic rings from 6-deoxy-D-allose

Abstract The synthesis of di-(6-deoxy-β- D -allofuranose) 1,5′:1′,5-dianhydride ( 8 ) from 6-deoxy- D -allose is described. Periodate oxidation of 8 , followed by borohydride reduction and acetylation, yielded a crystalline 2,4,7,9-tetra(acetoxymethyl)-5.10-dimethyl-1,3,6,8-tetraoxecane ( 3 ).

The alkenic unreactivity of mono- and bi-cyclic derivatives of 3,6-dihydro-2-(methylthio)-2H-thiopyran S,S,S′,S′-tetraoxide☆

Abstract The inertness of the alkenic bond towards electrophilic additions in 3- exo cyano-3-(methylthio)-2-thiabicyclo[2.2.1]hept-5-ene S,S,S′,S′ -tetraoxide ( 5 ), 3,6-dihydro-2-(methylthio)-2 H -thiopyran-2-carbonitrile S,S,S′,S′ -tetraoxide ( 3 ), and 2-(acetamidomethyl)-3,6-dihydro-2-(methylthio)-2 H -thiopyran S,S,S′,S′ -tetraoxide ( 4 ) is attributed to the “supra-annular effect” and field effects. Conformational analysis of a pentadeuterated derivative of 4 ( 10 ) is reported. On the basis of the 220-MHz 1 H n.m.r.-spectral data of 10 , the compound was concluded to adopt the 0 H 2 conformation in chloroform solution.