Tungsten halides deoxygenation

DEOXYGENATION WITH LOWER VALENT TUNGSTEN HALIDES... 

Sharpless KB, Umbreit MA, Nieh MT, Flood TC (1972) Lower Valent Tungsten Halides. A New Class of Reagents for Deoxygenation of Organic Molecules. J Am Chem Soc 94 6538... 

Deoxygenation. Sharpless et al.1 have prepared a series of lower valent tungsten halides from tungsten hexachloride as shown ... 

Lower valent tungsten halides are a new class of deoxygenation agents, e.g. for the conversion of carbonyl or epoxy compounds into olefins . A new reagent, generated in situ from iron pentacarbonyl and a small amount of base in moist solvents, selectively and efficiently hydrogenates the ethylenic portion of a,/ -unsaturated carbonyl compounds, such as ketones or lactones, under mild conditions. Aliphatic tert. amides can be easily reduced to alcohols by alkali metals in hexa-methylphosphoramide and a protic cosolvent such as tert-butanol. Aldehydes can be obtained from acids by catalytic reduction of intermediate carboxylic alkoxyformic anhydrides . Sec. nitro compds. are converted into ketones by the joint action of a nitrite ester and NaNOg under mild, non-acidic conditions . 

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