Diethyl Ether → Vitamin K

Beteiligte Stoffe

Reaktionsschritte

A solution of 1 mmol of pentacarbonyl[methoxy(phenyl)carbene]chromium and 1.1 mmol of 6,10,14,18-tetramethyl-5-nonadecen-2-yne from phytyl bromide (isomer ratio E/Z=90/10) in 5 ml of dibutyl ether is heated to 55° C. under nitrogen for 1 hour. After the removal of the solvent, the 1-naphthol-tricarbonyl-chromium complex can be isolated (yield 95%) by chromatography on silica gel at -30° C. with methylene chloride/pentane (2/1), or directly oxidised to the quinone after addition of 10 ml of ether by one-hours stirring with 1.5 mmol of silver (I) oxide in the presence of MgSO4. The obtained mixture is filtered, the solvent removed and the residue purified by chromatography at 10° C. on silica gel with pentane/ether (100/1). There is obtained vitamin K1(20) as a light yellow oil in a total yield of 56%.

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