Glycosyl esters of amino acids: Part V. synthesis and properties of 1-O-acylaminoacyl-α-and -β-D-glucopyranoses and 1-O-(L-β-aspartyl)-β-D-glucopyranose

Abstract Catalytic hydrogenation of the tetrabenzyl ethers of 1- O -acetamidoacyl- and 1- O - tert -butyloxycarbonylaminoacyl-α- and -β- D -glucopyranoses ( 1–6 ) afforded the corresponding 1- O -acylaminoacyl- D -glucopyranoses 8–13 which were fully characterised by physical methods and by conversion into the peracetylated derivatives 14–19 . The α anomers of 1- O - tert -butyloxycarbonylaminoacyl- D -glucopyranoses underwent 1→2 acyl migration, and, in order to characterize the rearrangement product of 1- O -( tert -butyloxycarbonyl- L -alanyl)-α- D -glucopyranose ( 12α ), 1,3,4,6-tetra- O -acetyl-2- O -( tert -butyloxycarbonyl- L -alanyl)-α- and -β- D -glucopyranoses ( 22 and 23 ) were synthesized by definitive methods. Initial studies of the simultaneous deprotection of the amino and hydroxyl functions were performed with D -glucose-amino acid 6-esters; catalytic hydrogenation of methyl 2,3,4-tri- O -benzyl-6- O -( N -benzyloxycarbonylglycyl)-β- D -glucopyranose ( 24 ) gave methyl 6- O -glycyl-β- D -glucopyranose ( 25 ) as the stable hydrochloride. Hydrogenolysis of the β anomer of 2,3,4,6-tetra- O -benzyl-1- O -[1-benzyl N -(benzyloxycarbonyl)- L -aspart-4-oyl]- D -glucopyranose ( 7 ) afforded 1- O -(L-β-aspartyl)-β- D -glucopyranose ( 27 ). The rates of hydrolysis of the unprotected D -glucose-amino acid 1 -ester 27 in water and in 0.1 M hydrochloric acid were compared with those of the D -glucose-amino acid 6-ester 25 .