Alok K. Awasthi

Palladium catalysed C-8 allylation and vinylation of adenosine, 2'-deoxyadenosine and 2',3'-dideoxyadenosine nucleosides

Abstract Using a coupling reaction between 8-iodo derivatives of O-TBDMS protected adenosine, 2′deoxyadenosine, 2′,3′-dideoxyadenosine and either vinyltributyltin or allyltributyltin with Pd(PPh 3 )4 catalysis, the corresponding 8-substituted nucleosides were obtained in excellent yields.

Inversion of configuration of α-trisubstituted (neopentyl) type secondary alcohols

Abstract A variety of hindered α-trisubstituted optically active secondary alcohols has been converted into their enantiomers by treating the corresponding triflates with KNO 2 in DMF in the presence of 18-crown-6 at room temperature.

Hypervalent iodine oxidation of trimethylsilyl enol ethers of ketones: a direct synthesis of α-keto triflates

Abstract α-Trifluoromethanesulfonoxy ketones (α-keto triflates) have been synthesized under very mild conditions by the reaction of silyl enol ethers of ketones and trimethylsily trifluormethanesulfonate/iodosobenzene in dichloromethane.

A Comvewiemt Synthesis of 1-Aminopolycycloalkames and Their Tosylate Salts

Abstract Syntheses of oridgehead 4-amino-l-bromopentacy-clo[4.3.0.02.5 O3,8.O4,7]nonan-9-one ethyl ene acetal (6), 4-iodocubyl-l-ammonium tosylate (8) and 1-adamantane ammonium tosylate (10) are described.

Solvolysis of cubyl trifluoromethanesulphonate: solvent and remote substituent effects

Cubyl trifluoromethanesulphonate solvolyses at a convenient rate and with a high sensitivity to solvent ionizing power; substituents on C-4 retard the solvolysis, modestly for methyl and enormously for methoxycarbonyl or halogen.

Conversion of thiocarbonyl into carbonyl in uracil, uridine, and Escherichia coli transfer RNA using hypervalent iodine oxidation

2-Thiouracil, 5-, and 6-methyl-2-thiouracil were converted into uracil, 5-, and 6-methyluracil by PhlO in acetone; the 4-thiouridine site in tRNA was transformed to uridine by Phl(OH)OSO2C6H4Me-p at pH 4.0.