Hiroyuki Terayama

Total synthesis of (-)-allosamidin, an insect chitinase inhibitor, employing chitin as a key starting material

Abstract (−)-Allosamidin ( 1 ), a novel insect chitinase inhibitor, was stereoselectively synthesized from di- and monosaccharidic constituens of chitin, N, N′-diacetylchitobiose ( 2 ) and D-glucosamine ( 3 ).

Stereocontrolled synthesis of (−)-allosamizoline using D-glucosamine as a chiral template

Abstract (−)-Allosamizoline (1), a core component of novel insect chitinase inhibitor, allosamidin (2), was stereoselectively synthesized from D-glucosamine (3), using an efficient ring contraction reaction as a key step.

Synthesis of demethylallosamidin, a yeast chitinase inhibitor; use of disaccharide glycosyl donor carrying novel neighboring group

Abstract In the synthesis of novel pseudotrisaccharide called demethylallosamidin, a thioglycoside carrying the 2-acetamido group served as an efficient glycosyl donor through undergoing specific N,O-isopropylidenation at the 2- and 3-positions which prohibits oxazoline ring formation during the glycosidation reaction.

SYNTHESIS OF A NOVEL AZAPSEUDODISACCHARIDE RELATED TO ALLOSAMIDIN EMPLOYING N, N'-DIACETYLCHITOBIOSE AS A KEY STARTING MATERIAL

Abstract Design and synthesis of a potential chitinase inhibitor 4, related to allosamidin (2), is described. Radical cyclization mediated by tributyltin hydride was applied for the first time to chitobiose-derived oxime ethers 9a,b to give four stereoisomers of an aminocyclopentane derivative connected to an N-acetyl-D-glucosamine residue at C-1 position. The major isomer 10b was efficiently converted into a novel pseudodisaccharide 4 via a series of cyclic-guanidine formation reaction.

Synthetic studies on a potential endoglycosidase inhibitor: Chemical conversion of N,N′-diacetylchitobiose into a pseudodisaccharide containing 2-acetamido-1,2-dideoxynojirimycin

Abstract The usefulness of N , N ′-diacetylchitobiose ( 1 ) as a starting material for syntheses of biologically active compounds was shown by converting allyl chitobioside 5 into O -(2-acetamido-2-deoxy-β-D-glucopyranosyl)-(1→4)-2-acetamido-1,2,5-trideoxy-1,5-imino-D-glucitol ( 2 ), which would be a potential glycosidase inhibitor. The conversion includes a discriminative modification of two amino groups existing in the disaccharide intermediate 8 , regioselective introduction of an azide group and construction of a piperidine ring utilizing an intramolecular aminocyclization.