In this work we describe a simple two step separation procedure for the separation and purification of short DNA fragments. The first step involves precipitating the DNA using the cationic surfactant dodecyltrimethylammonium bromide. Dodecyltrimethylammonium bromide, unlike cetyltrimethylammonium bromide will not precipitate DNA before complexation is complete thus providing a high purity DNA. The second step involves dissolution of the DNA-dodecyltrimethylammonium complex in 75% ethanol, followed by precipitation of the Sodium-DNA salt, by titrating in a salt solution. This method is particularly suited to purification of short fragments as it does not require high salt concentrations in the ethanol precipitation step, which can be damaging for short DNA. The ability of dodecyltrimethylammonium bromide to remove ethidium bromide from intercalation sites on the DNA is also discussed

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[reaction: see text]. The synthesis of D-lyxo-hexos-5-ulose (5-ketomannose, 1,5-dicarbonyl sugar), a synthetic precursor to the glycoprocessing inhibitor deoxymannojirimycin, was carried out by an in situ epoxidation and hydrolysis of a trimethylsilyl-protected 6-deoxyhex-5-enopyranoside followed by facile removal of the protecting groups. A novel nine-step synthesis of deoxymannojirimycin has also been achieved from methyl alpha-D-mannopyranoside; this involved methanolysis of epoxides derived from an acetylated 1-azido-6-deoxyhex-5-enopyranoside followed by deprotection and catalytic hydrogenation.

1-Deoxynojirimycin, 1-deoxymannojirimycin, and 1-deoxygalactostatin have been synthesized by epoxidation of tri-O-acetyl-6-deoxyhex-5-enopyranosyl azides followed by methanolysis, deacetylation, and catalytic hydrogenation. 1,6-Dideoxygalactostatin was obtained by the reaction of 2,3,4-tri-O-acetyl-6-deoxy-beta-L-arabino-hex-5-enopyranosyl azide with NIS in methanol followed by deacetylation and catalytic hydrogenation. The overall yields were 4.4-23.5% over seven to nine steps.

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