3,5-O-Isopropylidene-2-C-methyl-D-xylonolactone

Abstract

The ring size of both the lactone and the ketal protecting group in the title compound, C9H14O5, have been established by X‐ray crystallographic analysis. The crystal structure consists of hydrogen‐bonded spirals parallel to the b axis.

2-C-Methyl-D-lyxono-1,4-lactone

“…The structure of the minor isomer was confirmed as 2-C-methyl-d-xylono-1,4-lactone (3) by an X-ray structure of its 3,5-acetonide (Watkin et al, 2005). The major product 2-C-methyl-d-lyxono-1,4-lactone (4), initially isolated as an oil, slowly crystallized allowing the relative configuration at C-2 and the ring size of the lyxonolactone to be unambiguously assigned by X-ray crystallographic analysis.…”

3-C-Methyl-D-allono-1,5-lactone

“…The Kiliani reaction of ketoses and deoxyketoses with cyanide has provided an environmentally friendly procedure for the generation of a set of carbohydrate scaffolds with a branched carbon substituent at C-2 (Hotchkiss et al, 2004;Soengas et al, 2005). X-ray crystallographic analysis was vital in determining the structures of the products in these reactions (Punzo et al, 2006;Watkin et al, 2005). At present, free sugars and their lactones with a carbon branch at C-3 are essentially unknown.…”

2,5-Di-O-acetyl-3-C-methyl-D-lyxono-1,4-lactone

“…Branched sugar lactones bearing a C-2 methyl group may be accessed either by a Kiliani reaction on 1-deoxyketoses or by treatment of an Amadori ketose with aqueous calcium hydroxide (Hotchkiss et al, 2006). X-ray crystallographic analysis has been crucial in establishing the structures of the products in these reactions (Punzo et al, 2006;Watkin et al, 2005;Harding et al, 2005). Although these syntheses provide convenient access to C-2 carbon-branched carbohydrates, there are very few reports of sugars with a carbon branch at C-3; a 3-C-methylpentonolactone of unknown stereochemistry has been isolated from cigarette smoke (Schumacher et al, 1977) and 3-Cmethyl-d-mannose is one of the components of the trisaccharide repeating unit of the polysaccharide from Helicobacter Pylori (Kwon et al, 2004).…”