Mikael Bols

Mikael Bols

Abstract Dissaccharides containing 1,2-cis glycoside linkages were synthesized by an efficient stereocontrolled two step process involving a silicon tethering step, to a dimethylsilyl acetal followed by intramolecular glycosidation with N-iodosuccinimide in nitromethane.

Mikael Bols; Inge Lundt; Christian Pedersen

Abstract (R)-Carnitine was prepared by two simple, short and efficient syntheses starting from ld -galactono-1,4-lactone.

Christel Barbaud; Mikael Bols; Inge Lundt; Michael R. Sierks

Abstract A number of synthetic routes to the first pseudo-C-disaccharide ever prepared has been studied. The compound, methyl 7-(( 1S , 3R , 4R , 5S , 6S )-1-amino-3-hydroxymethyl-4,5,6trihydroxycyclohexyl) -6,7-dideoxy-α-D- gluco -heptopyranoside ( 1 ), is structurally related to cellobiose, but includes a crucial amino-functionality at the pseudoanomeric centre. It was prepared by 1,2-addition of the anion of methyl 6,7-dideoxy-2,3,4-tri- O -benzyl-α-D- gluco -hept-6ynopyranoside to ( 4R , 5S , 6R )-3-benzyloxymethyl-4,5,6-tribenzyloxy-2-cyclohexenone followed by stereoselective conversion of the tertiary alcohol to azide and finally reduction.

Mikael Bols; Inge Lundt; Erik Rytter Ottosen

Abstract The following compounds have been prepared for use as glycosyl donors: 1,3,4-tri- O -acetyl-2,6-dideoxy-2-fluoro-α,β- l -glucopyranose ( 5a ), 1,3,4-tri- O -acetyl-2,6-dideoxy-α,β- l - arabino -hexopyranose ( 7a ), 1,3,4-tri- O -acetyl-2-azido-2,6-dideoxy-α,β- l -mannopyranose ( 8a ), 1,2,4-tri- O -acetyl-3,6-dideoxy-α, l - arabino - hexopyranose ( 13a ), and 1,2,3-tri- O -acetyl-4,6-dideoxy-α- ( 15a ) and -β- l - lyxo -hexopyranose ( 15b ).

Gitte Mikkelsen; Troels V. Christensen; Mikael Bols; Inge Lundt; Michael R. Sierks

Abstract β-L-xylopyranosides of a number of both known and new hydroxypyrrolidines were prepared.

Mikael Bols; Lise Binderup; Jytte Hansen; Poul Rasmussen

Glycosides of aranciamycinone were prepared by glycosylation with sugar acetates and trimethylsilyl triflate in dichloromethane. Glycosides of the following sugars were prepared: alpha-L-rhamnopyranose, beta-D-glucopyranose, beta-D-ribopyranose, beta-D-xylopyranose, alpha-L-fucopyranose, 2-azido-2,6-dideoxy-alpha-L-mannopyranose, 2,6-dideoxy-alpha-L-arabino-hexopyranose, 3,6-dideoxy-alpha-L-arabino-hexopyranose, and 4,6-dideoxy-alpha-L-lyxo-hexopyranose. The new glycosides were tested for inhibition of Clostridium histolyticum collagenase and Yoshida Sarcoma tumor cells.

Mikael Bols; Helle Grubbe; Tina M. Jespersen; Walter A. Szarek

Abstract (Benzyloxymethyl)lithium, generated in situ from butyllithium and (benzyloxymethyl)tri- n -butylstannane, was found to be an efficient reagent for the monohydroxymethylation of aldono-1,4-lactones to form ketoses. Thus, 4-hydroxy butanoic-1,4-lactone, 2-deoxy-2-fluoro-3,5-di- O -(methoxymethyl)- d -arabinono-1,4-lactone, 2,3,5-tri- O -(methoxymethyl)- d -arabinono-1,4-lactone, 5- O -(methoxymethyl)-2,3- O -methylidene- d -ribono-1,4-lactone, 2,3,5,6-tetra- O -(methoxymethyl)- d -altrono-1,4-lactone, 2,3:5,6-di- O -isopropylidene- d -gulono-1,4-lactone and 2,3- O -isopropylidene- l -erythrono-1,4-lactone were respectively converted to 1-benzyloxy-5-hydroxy-2-pentanone, 1- O -benzyl-3-deoxy-3-fluoro-4,6-di- O -(methoxymethyl)- d -fructofuranose, 1- O -benzyl-3,4,6-tri- O -(methoxymethyl)- d -fructofuranose, 1- O -benzyl-6- O -(methoxymethyl)-2,3- O -methylidene- d -psicofuranose, 1- O -benzyl-3,4,6,7-tetra- O -(methoxymethyl)- d - altro -heptulofuranose, 1- O -benzyl-3,4:6,7-di- O -isopropylidene- d - gulo -heptulofuranose, and 1- O -benzyl-3,4- O -isopropylidene- l - erythro - pentulofuranose in 63–81% yields. By deprotection of 1- O -benzyl-3-deoxy-3-fluoro-4,6-di- O -(methoxymethyl)- d -fructose, 3-deoxy-3-fluoro- d -fructose was prepared for the first time.

Tina M. Jespersen; Wenling Dong; Michael R. Sierks; Troels Skrydstrup; Inge Lundt; Mikael Bols

Tina M. Jespersen; Wenling Dong; Michael R. Sierks; Troels Skrydstrup; Inge Lundt; Mikael Bols

Mikael Bols; Inge Lundt; Dagfinn W. Aksnes; Trond. Brekke; Knut Maartmann-Moe; H. H. Tønnesen; Tadashi Tokii