476487-80-6

Upstream product

• 14125-76-9 1,5-anhydro-2,3,4-tri-O-acetyl-D-threo-pent-1-enitol 
• 100-51-6 benzyl alcohol 
• 476487-78-2 2,3,4-tri-O-acetyl-1,5-anhydro-L-erythro-pent-1-enitol 
• 112482-93-6 benzyl 3,4-dideoxy-α-D-glycero-pent-3-enopyranoside 
• 70798-32-2 benzyl 2-O-acetyl-3,4-dideoxy-α-D-glycero-pent-3-enopyranoside 
• 70798-28-6 benzyl 2-O-acetyl-β-L-arabinopyranoside 3,4-thionocarbonate 
• 856099-26-8 benzyl 2-O-acetyl-3,4-di-O-methylsulfonyl-β-L-arabinopyranoside 
• 51830-02-5 bromo-2,3,4-O-triacetyl-α/β-L-arabinopyranoside 
• 62446-93-9 1,2,3,4-tetra-O-acetyl-D-xylopyranose 
• 87-72-9 D-Xylose 
• 1233-03-0 1,2,3,4-tetra-O-acetyl-L-arabinopyranose 
• 18403-22-0 (3aS,6S,7R,7aR)-6-Benzyloxy-2,2-dimethyl-tetrahydro-[1,3]dioxolo[4,5-c]pyran-7-ol 
• 7473-38-3 benzyl β-L-arabinopyranoside 
• 70798-30-0 benzyl 2-O-acetyl-3,4-di-O-isopropylidene-β-L-arabinopyranoside 

Downstream Products

• 391928-94-2 benzyl 3,4-dideoxy-α-L-glycero-pent-3-enopyranoside 

Relevant academic research and scientific papers

Stereoselective total synthesis of all the stereoisomers of (+)- and (?)-febrifugine and halofuginone

A convenient method for the total synthesis of all the stereoisomers of febrifugine and halofuginone using D-arabinose and L-arabinose as the key starting materials is reported. Apart from the inherent stereocenters in these pentose sugars, the method utilizes the selective hydrogenolysis of the anomeric O-benzyl group, stereoselective Grignard reaction and Wacker oxidation as the key steps to obtain the important precursors for the total synthesis.

Synthesis of enantiomerically pure enones (2-benzyloxypyran-3-ones)derived from pentoses

The useful synthons sugar enones (2-benzyloxypyran-3-ones)derived from pentoses have been prepared starting from 2-acetoxyglycals or benzyl pentopyranosides. The glycals were glycosylated with benzyl alcohol in the presence of a Lewis acid (SnCl4/su

Enantiospecific synthesis of both enantiomers of 2-benzyloxydihydropyran-3- ones from arabinose

Approaches to the enantioselective synthesis of the useful building blocks (2R)- and (2S)-2-benzyloxy-2(H)-pyran-3(6H)-one (12 and 17, respectively) are described. The most direct and highly yielding route for the synthesis of 12 was based on the 'one-pot

Stereocontrolled Diels - Alder cycloadditions of sugar-derived dihydropyranones with dienes

2-Acetoxy-3,4-di-O-acetyl-D-arabinal (6), similar to its D-xylo analogue 4, reacted with benzyl alcohol by the tin(IV) chloride-promoted glycosylation to produce optically active (S)-2-benzyloxy-2H-pyran-3(6H)-one (8a). The L-arabinal derivative (5) gave 9a, the dihydropyranone enantiomer of 8a. These results indicated that the configuration of the C-4 stereocenter in the starting glycal defines the configuration of the new chiral center in the resulting dihydropyranone. The influence of other catalysts (BF3 or iodine) employed for the glycosylation on the optical purity of the dihydropyranone was studied. Enantiomerically pure dihydropyranones 8b and 9c were obtained using chiral alcohols ((R)- and (S)-2-octanol, respectively) as glycosylating agents. Compounds 8a,b and 9a,c proved to be reactive dienophiles in thermal and Lewis acid-promoted Diels - Alder reactions. The addition of 2,3-dimethylbutadiene, cyclopentadiene, and 1,3-cyclohexadiene to the β-pyranones 8a,b led to the corresponding adducts 10a,b, 12a,b, and 16a,b as major products. Enantiomeric cycloadducts were synthesized from the α-pyranones 9a,c. The main products were formed by highly facial-diastereoselective addition of dienes to the pyranone ring, guided by the sterical hindrance of the alkoxy substituent of the C-2 stereocenter. As cycloadditions with cycloalkadienes were also highly endo diastereoselective, these reactions gave access to pure tetrahydrobenzopyranones that carry a multitude of stereogenic centers installed in a predictable way.

Synthesis of optically active 2-alkoxy-2H-pyran-3(6H)-ones. Their use as dienophiles in Diels-Alder cycloadditions

Optically active 2-alkoxy-2H-pyran-3(6H)-ones (4a-d) were synthesized in one step by the tin(IV) chloride-promoted glycosylation and rearrangement of the 2-acetoxy-3,4-di-O-acetyl-D-xylal (3) prepared from D-xylose (1). The absolute configuration of the new stereocenter at C-2 was determined by chemical transformation of the dihydropyranones 4a and 4b into the known alkyl pentopyranosides (7a and 7b, respectively). Also, from 1H NMR experiments using a chiral ytterbium shift reagent, the enantiomeric excesses for 4a (> 86%) and 4b (>77%) were established. Enantiomerically pure 4c and 4d were obtained by reaction of 3 with chiral 2-octanol (R and S, respectively). Dihydropyranones 4a-d were employed as dienophiles in Diels-Alder cycloadditions with 2,3-dimethylbutadiene and butadiene. Under thermal conditions, only moderate yields (～50%) of cycloadducts 9a-c and 10a were respectively obtained with good diastereofacial selectivity (> 80%). Optimized Lewis acid promoted cycloadditions led to 9a-d and 10a,c in higher yields (～80%) and with higher diastereoselectivities (> 94%). The major products were formed by approach of the dienes from the less hindered face of the dihydropyranones, and the minor products (such as 11a) were formed by addition from the opposite side. Furthermore, cycloadduct 9a was stable in an alkaline solution, whereas 11a underwent epimerization under the same conditions.