Oxidative cleavage of 4,6-O-ethylidene glucose (I) with sodium periodate afforded 5-hydroxy-2-methyl-1,3-dioxan-4-carbaldehyde (II), which was reduced to alcohol (III) using sodium borohydride (1). Protection of the primary hydroxyl of (III) with tert-butyldimethylsilyl chloride, followed by Moffatt oxidation of the secondary hydroxyl group provided ketone (V). Subsequent Wittig reaction of (V) with ethyl (triphenylphosphoranylidene)acetate gave a mixture of E,Z unsaturated esters (VIa-b). Catalytic hydrogenation of the double bond of (VIa-b) produced the saturated ester (VIIa-b) as a diastereomeric mixture that was separated by column chromatography. Diisobutylaluminum hydride reduction of the desired ester furnished aldehyde (VIII), which was subjected to a Wittig reaction with the sodium salt of (4-carboxybutyl)triphenylphosphonium bromide (IX) yielding acid (X). Conversion of (X) to the methyl ester (XI) by methylation with iodomethane and K2CO3, followed by desilylation with Bu4NF afforded hydroxy ester (XII). Oxidation of the alcohol group of (XII) with Collins' reagent gave aldehyde (XIII). This was converted to the thiosemicarbazone (XV) upon condensation with phenyl thiosemicarbazide (XIV). Finally, the methyl ester group of (XV) was hydrolyzed, and the carboxylic acid was converted to the corresponding sodium salt.

Oxidative cleavage of 4,6-O-ethylidene glucose (I) with sodium periodate afforded 5-hydroxy-2-methyl-1,3-dioxan-4-carbaldehyde (II), which was reduced to alcohol (III) using sodium borohydride (1). Protection of the primary hydroxyl of (III) with tert-butyldimethylsilyl chloride, followed by Moffatt oxidation of the secondary hydroxyl group provided ketone (V). Subsequent Wittig reaction of (V) with ethyl (triphenylphosphoranylidene)acetate gave a mixture of E,Z unsaturated esters (VIa-b). Catalytic hydrogenation of the double bond of (VIa-b) produced the saturated ester (VIIa-b) as a diastereomeric mixture that was separated by column chromatography. Diisobutylaluminum hydride reduction of the desired ester furnished aldehyde (VIII), which was subjected to a Wittig reaction with the sodium salt of (4-carboxybutyl)triphenylphosphonium bromide (IX) yielding acid (X). Conversion of (X) to the methyl ester (XI) by methylation with iodomethane and K2CO3, followed by desilylation with Bu4NF afforded hydroxy ester (XII). Oxidation of the alcohol group of (XII) with Collins' reagent gave aldehyde (XIII). This was converted to the thiosemicarbazone (XV) upon condensation with phenyl thiosemicarbazide (XIV). Finally, the methyl ester group of (XV) was hydrolyzed, and the carboxylic acid was converted to the corresponding sodium salt.