Diethylamine → HCID 22794144, compound

Participants

Reaction Conditions

Reaction Steps

A solution of crude 9-methoxyimino-5-(S)-hydroxydecanoic acid lactone (144.4 g.) in tetrahydrofuran (850 ml; dry) was cooled under nitrogen in a dry ice-acetone bath to -60°C. A 2.24 molar vinyl magnesium-chloride in tetrahydrofuran solution (159 ml; 70% excess) was added at such a rate that the temperature remained at -50° to -55°C. during 10 min. The reaction mixture was then stirred for an additional 20 min. at -55 to -60°C. after which it was cooled to -70°C. and at this temperature carefully hydrolyzed with methanol (24 ml). The resulting mixture was poured into a mixture of saturated ammonium chloride solution (250 ml), ether (700 ml) and ice (100 g.). The aqueous phase was extracted several times with ether. The ethers were washed with brine and then dried over anhydrous sodium sulfate to give a solution containing 6(S)--(4-methoxyiminopentyl)-2-vinyl-tetrahydropyran-2-ol and its tautomer. Diethylamine (85 ml) was added to this ether solution and the mixture was allowed to stand at room temperature for 1 hr. Filtration and solvent removal affored crude 2(S)-diethylaminoethyl6(S)-(4-methoxyiminopentyl)-tetrohydropyran-2-ol (62.5 g.). This material was dissolved in acetone (850 ml) and treated with 2N sulfuric acid (610 ml) at 0°C. After the reaction mixture was allowed to stand at room temperature for 25 hr, it was concentrated to a volume of 650 ml at 30°C. in vacuo and then extracted with ether. The ether was washed with brine. The aqueous phase was treated with 10N sodium hydroxide solution (155 ml) at 0°C. The resulting mixture was extracted with ether, the ether was washed with brine and then dried over anhydrous sodium sulfate. Filtration and solvent removal afforded pure 2(S)-diethylaminoethyl-6(S)-(4-oxopentyl)-tetrahydropyran-2-ol as a yellow oil (45.5 g.). A sample was chromatographed on aluminum oxide (grade III). Elution with benzene-ether 9:1, 4:1 and 2:1 afforded an analytically pure sample of product as a colorless oil; [α]D 25 -39.91° (C=1.3832 in benzene).

Provenance & Evidence