Nach Schutz der C-1-bis C-3-Position wird L-Rhamnose (1) zur Methyl-2,3-U-isopropyliden-~~-~-rhamnofuranosid-5-ulose (3) oxidiert. Grignard-Reaktion liefert Methyl-2,3-0-isopropyliden-5,5-di-C-methyl-a-~-lyxofuranosid (4). Nach Hydrolyse wird die 5J-Di-C-methyl-IAyxopyranose (5) isoliert. Reaktion mit Aceton, Methanol und Schwefelsaure liefert 2,3-0-Isopropyliden-5,5-di-C-methyl-r,-lyxopyranose (6) und 4 als Nebenprodukt. Phasentransferkatalysierte 4-0-Methylerung ergibt 2,3-0-Isopropyliden-4-0-methyl-5,5-di-C-methyl-L-lyxopyranose (7). Nach saurer Hydrolyse erhalt man die Noviose (8).
A New, Simple Synthesis of NovioseAfter protection of the C-I up to thc C-3 position L-Rhamnosc (1) is oxidized to yield methyl 2,3-0-isopropylidene-~-r.-rhamnofuranos~d-5-ulose (3). Grignard reaction affords methyl 2,3-0-isopropylidene-5,5-di-C-methyl-~~-~-lyxofuranoside (4). After hydrolysis 5,5-di-C-methyl-L-lyxopyranose (5) is isolated. Reaction with acetone, methanol, and sulfuric acid gives 2,3-0-isopropylidene-5,5-di-C-methyl-~-lyxopyranose (6) and 4 as a by-product. Phase transfer-catalyzed 4-0-methylation yields 2,3-0-isopropylidene-4-U-methyl-5,5-di-C-methyl-~lyxopyranose (7). After acid hydrolysis the noviose (8) is obtained.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.