A novel entry to C-glycals via diethylzinc-mediated umpolung of π-allyl palladium derived from 1-exo-methylene 2,3-anhydrofuranoses

1‐exo‐Alkylidene‐2,3‐anhydrofuranoses: Valuable Synthons in the Preparation of Furanose‐Based Templates

“…Compound 1a is able to react smoothly (through the π-allyl palladium complex 36, [27] Scheme 6) with nucleophiles, [11] vinylstannanes [27,28] or, after treatment with ZnEt 2 , with electrophiles [29] to give highly functionalized C-1 glycals [27,30] such as 37-39.…”

Synthesis of C‐1 Alkyl and Aryl Glycals from Pyranosyl or Furanosyl Chlorides by Treatment with Organolithium Reagents

“…We recently reported a method for the preparation of furanosyl C-1 glycals based on the reaction of π-allyl palladium complexes generated from epoxy-exo-glycals (Scheme 1f). [46] In contrast, some time ago, as part of our interest in the reaction of sugar derivatives with organolithium reagents, [47] we described the synthesis of pyranosyl C-1 glycals by reaction of glycosyl chlorides with organolithium reagents. [48,49] In this paper we would like to report on the continuation of our studies on the scope of the transformation, including its extension to the preparation of furanoid C-1 glycals.…”

One-pot construction of carbohydrate scaffolds mediated by metal catalysts

“…This proceeded by domino epoxide opening via formation of an allyl-Zn intermediate (100) from an initially formed p-allyl-Pd intermediate, followed by subsequent attack by the electrophile, and ultimately generated the corresponding new functionalised C-glycal derivatives 101 (Scheme 30). 44 Although the protocol was compatible with highly oxygenated substrates and was highly regioselective in reaction with aldehyde electrophile generating always 1,5-diol, but the stereoselectivity varied from moderate to excellent depending upon the reaction partners.…”