174270-87-2

Upstream product

• 100906-41-0 (5S,6S)-5-(benzyloxy)-6-(hydroxymethyl)-5,6-dihydro-2H-pyran-2-one 
• 18162-48-6 tert-butyldimethylsilyl chloride 
• 340699-28-7 ethyl (2R,3S)-2-O-benzyl-3,4-O-isopropylidene-2,3,4-trihydroxybutanoate 
• 100906-44-3 (Z)-(S)-4-Benzyloxy-4-((S)-2,2-dimethyl-[1,3]dioxolan-4-yl)-but-2-enoic acid 
• 100-52-7 benzaldehyde 
• 100906-43-2 (Z,S,S)-methyl 4-O-benzyl-5,6-di-O-isopropylidene-4,5,6-trihydroxy-2-hexenoate 
• 100906-42-1 2-O-benzyl-3,4-O-isopropylidene-L-threose 
• 84379-51-1 2-O-benzyl-L-threitol 
• 38270-72-3 dimethyl 2,3-O-benzylidene-L-tartrate 
• 100906-45-4 (5S,6S)-6-(benzyloxy)-2,2-dimethyl-1,3-dioxepan-5-ol 
• 866771-99-5 [(4'R,5'R)-5'-(benzyloxy)-2',2'-dimethyl-1',3'-dioxan-4'-yl]methanol 

Downstream Products

• 185627-30-9 ((2S,3S,6R)-3-Benzyloxy-6-ethoxy-3,6-dihydro-2H-pyran-2-ylmethoxy)-tert-butyl-dimethyl-silane 
• 185627-33-2 ((2S,3S,6R)-3-Benzyloxy-6-ethoxy-3,6-dihydro-2H-pyran-2-yl)-methanol 

Relevant academic research and scientific papers

Synthesis of C1–C11 eribulin fragment and its diastereomeric analogues

A practical stereoselective synthesis of the central C1–C10 fragment of eribulin and its two diastereomeric analogues is developed. Our approach relied on the use of L-ascorbic acid as the starting material which allowed accessing a key intermediate with a syn diol moiety (C9 and C10 of eribulin) and a carboxylic ester group. A functionalized six membered lactone having several required hydroxyl groups was then obtained. In a number of steps, the lactone was converted to an intermediate for our key oxa-Michael reaction. A regio- and stereocontrolled intramolecular oxa-Michael reaction completed the synthesis of the C1–11 fragment having a trans-fused tetrahydropyrans with the exact stereochemistry of various hydroxyl groups, as in eribulin.

Stereoselective syntheses and reactions of chiral oxygenated α,β-unsaturated-γ- and δ-lactones

The syntheses of the chiral α,β-unsaturated lactones (+)-5, (-)-6, (+)-8, (+)-9, and (+)-10 have been efficiently achieved from readily available starting materials. The lactone (+)-5 has been synthesized in 7 steps from (R,R)-dimethyl tartrate (38-43% overall yield). The use of (+)-5 in formal syntheses of natural (+)-asperlin 4 and advanced intermediates for (+)-olguine 2 are also reported. The lactone (-)-6 has been prepared in 5 steps from (R)-malic and (44-50% overall yield). It can be a useful precursor for the syntheses of branched chain and deoxy nucleoside analogues. The preparation of (-)-6 constitutes formal syntheses of natural (+)-eldanolide 53 and the (+)-Geissman-Waiss lactone 54 (an intermediate for the syntheses of a variety of pyrrolizidine alkaloids). The lactones (+)-8, (+)-9 and (+)-10 have been synthesized from 3,4-di-O-acetyl-L-rhamnal 58. The highly diastereoselective transformations of (+)-9 and (+)-10, through sequential conjugate nucleophilic addition and enolate reaction, into densely functionalized chiral γ-lactones 12 are also reported. Copyright (C) Elsevier Science Ltd.