Aluminium lithium hydride → 1,1-dimethylethyl 4-(3,4-dichlorophenyl)-5-(hydroxymethyl)-2-methyl-3,6-dihydro-1(2H)-pyridinecarboxylate

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Reaction Conditions

Reaction Steps

A mixture of regioisomers 1-(1,1-dimethylethyl) 3-ethyl 4-(3,4-dichlorophenyl)-6-methyl-5,6-dihydro-1,3(2H)-pyridinedicarboxylate and 1-(1,1-dimethylethyl) 3-ethyl 4-(3,4-dichlorophenyl)-2-methyl-5,6-dihydro-1,3(2H)-pyridinedicarboxylate (P21, 0.45 g) was dissolved in toluene (15 mL) and cooled to −20° C. Lithium aluminium hydride 1.0M in THF (0.869 mL) was added dropwise at −20° C. and the mixture was stirred at this temperature for 2 h. The reaction was then quenched with a saturated solution of NH4Cl (10 mL) and diluted with ethyl acetate (20 mL); the organic layer was separated, washed with water (20 mL), dried and concentrated in vacuo. Purification by chromatography on silica gel eluting with a gradient 100% cyclohexane-50% cyclohexane/ethyl acetate afforded 240 mg of title compound as colourless oil. The structure of the major regioisomer was confirmed by nOe NMR experiments.

Provenance & Evidence