A convenient, high-yield synthesis of l-oleandrose and l-oleandral

A short, practical synthesis of l -oleandrose (2,6-dideoxy-3-O-methyl- l -arabino-hexose) from l -arabinose has been achieved. The synthesis is satisfactory for large-scale preparation of oleandrosylating intermediates, and employs dithiolane formation for protection of the aldehyde group during deoxygenation and methylation steps, and Wittig chain-extension to 2-deoxyhexose derivatives. Useful intermediates in the introduction of oleandrose glycosides into natural products, such as the 1,4-dibenzoates and the methyl glycosides, were prepared and characterized. l -Oleandral (1,5-anhydro-2,6-dideoxy-3-O-methyl- l -arabino-hex-1-enitol), another useful intermediate for glycosylation, was prepared from 3,4-di-O-acetyl- l -rhamnal by deacetylation, and regioselective methylation with stannous chloride-diazomethane.