ABSTRACT
Certain pterins having a hydroxyalkyl side chain at C-6 have been found as glycosidic forms in certain prokaryotes, such as 2'-O-(α-D-glucopyranosyl)biopterin from various kinds of cyanobacteria, and limipterin from a green sulfur photosynthetic bacterium. Synthetic studies on glycosides of biopterin and related pterins have been made in view of the structural proof as well as for closer examination of their biological activities and functions. The syntheses of these natural pterin glycosides have effectively been achieved, mostly through appropriately protected N(2) -(N,N-dimethylaminomethylene)-3-[2-(4-nitrophenyl)ethyl]pterin derivatives as glycosyl acceptors, and are reviewed here.
Subject(s)
Biopterins , Glycosylation , Pterins , Biopterins/chemical synthesis , Biopterins/chemistry , Glycosides/chemical synthesis , Glycosides/chemistry , Molecular Structure , Pteridines/chemistry , Pterins/chemical synthesis , Pterins/chemistryABSTRACT
N(2)-(N,N-Dimethylaminomethylene)-1'-O-(4-methoxybenzyl)-3-[2-(4-nitrophenyl)ethyl]-L-threo-biopterin (14) was prepared from L-xylose in an 11-step-sequence. The first synthesis of tepidopterin (3) was achieved by treatment of 14 with 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl bromide in the presence of silver triflate and tetramethylurea, followed by removal of the protecting groups.
Subject(s)
Biopterins/analogs & derivatives , Pterins/chemistry , Biopterins/chemical synthesis , Biopterins/chemistry , Bromides/chemistry , Carbohydrate Conformation , Carbohydrates/chemistry , Glycosides/chemistry , Magnetic Resonance Spectroscopy , Mesylates/chemistry , Methylurea Compounds/chemistry , Models, Chemical , Oligosaccharides/chemistry , Protons , Xylose/chemistryABSTRACT
Acetalation of sucrose with 2,2-dimethoxypropane in 1,4-dioxane in the presence of p-toluenesulfonic acid, followed by acetylation, afforded methyl 4,6-di-O-acetyl-1,3-O-isopropylidene-alpha-D-fructofuranoside and 4-O-acetyl-2,3:5,6-di-O-isopropylidene-D-glucose dimethyl acetal as major products, while tosylation of the intermediate acetals provided methyl 6-O-tosyl-1,3-O-isopropylidene-alpha-D-fructofuranose.
Subject(s)
Alkenes/chemical synthesis , Fructose/analogs & derivatives , Fructose/chemical synthesis , Glucose/analogs & derivatives , Glucose/chemical synthesis , Sucrose/chemistry , Alkenes/chemistry , Fructose/chemistry , Glucose/chemistry , Molecular StructureABSTRACT
3,4-Di-O-benzyl-6-deoxy-6-diethoxyphosphinyl-1,2-O-isopropylidene-beta-D-fructofuranose (13) was prepared from the known 1,2-O-isopropylidene-6-O-tosyl-beta-D-fructofuranose in five steps. Reduction of 13 with sodium dihydrobis(2-methoxyethoxy)aluminate, followed by the action of hydrochloric acid and then hydrogen peroxide, afforded the 6-deoxy-6-hydroxyphosphinyl-D-fructopyranose derivative. This was converted into the 1,2,3,4,5-penta-O-acetyl-6-deoxy-6-methoxyphosphinyl-D-fructopyranoses, whose structure and conformation were established by 1H NMR spectroscopy.
Subject(s)
Fructose/chemistry , Fructose/chemical synthesis , Organophosphorus Compounds/chemistry , Organophosphorus Compounds/chemical synthesis , Fructose/analogs & derivatives , Magnetic Resonance Spectroscopy , Molecular Sequence Data , Molecular Structure , Phosphorus IsotopesABSTRACT
The addition of dimethyl phosphonate to six different hexofuranos-5-uloses in the presence of DBU, followed by esterification with methoxalyl chloride and then radical reduction, afforded 5-deoxy-5-dimethoxyphosphinyl-D- and L-hexofuranoses. The stereoselectivity of the deoxygenation and possible transition-state models are discussed.
Subject(s)
Fucose/analogs & derivatives , Fucose/chemical synthesis , Glucose/analogs & derivatives , Glucose/chemical synthesis , Mannose/analogs & derivatives , Mannose/chemical synthesis , Oxygen/chemistry , Fucose/chemistry , Magnetic Resonance Spectroscopy , Molecular Conformation , Molecular Structure , StereoisomerismABSTRACT
1H NMR spectroscopy of phosphorus containing hetero sugars (phospha sugars), revealed the alpha and beta configurations and chair conformations for 3-acetamido-1,4-di-O-acetyl-2,3,5-trideoxy-5-C-(isopropylphosphinyl)-alpha- and beta-D-erythro-pentopyranoses. The conformation of the title compounds was determined by 1H NMR as 1C4 in CDCl3 and the conformation was in accord with that in solid state determined by X-ray crystallographic analysis.
