Diethyl Ether → 2-[6-(Tetrahydro-pyran-2-yloxy)-hexyl]-malonic acid diethyl ester

Participants

Reaction Conditions

Reaction Steps

Sodium (1.13 g, 49 mmol) in small quantities was dissolved in dry ethanol (100 ml) with constant stirring under a blanket of dry nitrogen. Diethyl malonate (8.0 g, 50 mmol) was added in one portion and the solution heated at 60° C. for 1 hour. 2-(6-Chloro-hexyloxy)-tetrahydropyran (9.3 g, 42.2 mmol) was added in one portion and the temperature raised to 75-80° C. and maintained at this level for 24 hours. After cooling, the inorganic solid was removed by filtration and solvent evaporated from the filtrate. The residue was dissolved in CH2Cl2 (50 ml), extracted with water (30 ml×2), dried (MgSO4) filtered and volatiles removed to leave a pale yellow oil. This oil was subject to chromatography on silica gel using pet ether 40:60/ether (200:40) as the eluent. The required product eluted with an rf=0.15 and was isolated as a colourless oil. Yield 8.7 g, (60%).

Provenance & Evidence