Ish K. Khanna

The mild and selective N-debenzylation of tertiary alkylamines using β-trimethylsilylethyl chloroformate.

Abstract Benzyl groups are efficiently and selectively cleaved from tertiary alkylamines using β-trimethylsilylethyl chloroformate. This general method is compatible with a wide range of functionality because it does not require strong hydrolytic or acidic solvolytic conditions.

A Short and Practical Synthesis of 1-Deoxynojirimycin

Abstract The potent glucosidase inhibitor 1-deoxynojirimycin was synthesized from L-sorbose using a short synthesis and only one protecting group. The last step, which constituted the removal of an acetonide protecting group and an intramolecular reductive amination, was accomplished on an acidic lon-exchange resin. This provided a synthesis capable of being operated on a multi-kilogram scale.

Nucleophilic Opening of N-Carboalkoxy-2,3-anhydro-1-deoxymannojirimycin. A Useful Method for the Syntheses of 2-, 3- and 2,3-Disubstituted 1-Deoxynojirimycin Analogs

Abstract A useful methodology for the synthesis of a number of 2-, 3- and 2,3-disubstituted deoxynojirimycin analogs is reported. It has been found that the epoxides in stereoselectively synthesized N-carboalkoxy-2,3-anhydro-1-deoxymannojirimycins (4 and 5) react with N-, S- and F- nucleophiles to give a mixture of gluco and altro products. The 3-azido altro compound (12b) yields the desired gluco derivative (40) by oxidation, in situ epimerization at C-3, followed by stereoselective reduction of the carbonyl group. The azido intermediate (12a) affords the 2,3-diazido gluco compound (51) by double inversion at C-3. Attempts have been made to understand the factors contributing to the opening of epoxides (4, 5 and 9) by different nucleophiles.

THE SYNTHESIS OF 1,5-DIDEOXY-1,5-(ALKYL)IMINO-2-C-METHYL-D-GLUCITOLS

The regio- and stereoselective synthesis of the title compounds 3 and 4 has been accomplished starting with deoxynojirimycin. The factors affecting the stereochemical outcome of Grignard addition to the key carbonyl intermediate are discussed.

Regiospecific addition of Grignard reagents to the 4-position of activated imidazo[4,5-c]pyridine. A convenient method for the synthesis of 4-alkyl(ary

Abstract The addition of Grignard reagents to 5-acylimidazopyridinium salts gives 4-substituted 5-acyl-4,5-dihydroimidazopyridines. This reaction was utilized t

Metallation of rigid 2-aryl-1,3-dioxanes

Abstract Regioselective metallation and alkylation/acylation of 2-aryl-1,3-dioxanes was achieved in high yield.