ChemInform Abstract: COMPETITIVE FORMATION OF PERACETYLATED α‐L‐ARABINOPYRANOSIDES AND β‐L‐ARABINOPYRANOSE 1,2‐(ALKYL ORTHOACETATES) IN KOENIGS‐KNORR CONDENSATIONS

Abstract

Bei der Reaktion der Halogenose (I) mit den Alkoholen (II) werden Gemische der Glycoside (III) und der Orthoester (IV) gebildet, deren Zusammensetzungen in Abhängigkeit vom Lösungsmittel untersucht werden.

A Total Synthesis of OSW-1

“…Monosaccharides as glycosyl acceptors and donors employed in this synthesis were prepared from L-arabinose and D-xylose, respectively (Scheme 2). After 12 was obtained from Larabinose as reported, 32 it was regioselectively p-methoxybenzxylated with the assist of dibutyltin complex to afford 13, which was directly subjected to acetolysis to give the desired glycosyl acceptor 14. In contrast to galactose derivatives in which 3-OH is usually more reactive than 4-OH, in 12, 4-OH was more reactive than 3-OH, probably because, as a pentose, arabinose has a less hindered 4-OH.…”