Pivalaldehyde → Methyl (Z)-2-[(tert-butoxycarbonyl)amino]-4,4-dimethylpent-2-enoate

Participants

Reaction Conditions

Reaction Steps

Pivalaldehyde (303.2 g, 3.41 mol, 10 eq.) and methyl {[(tert-butoxy)carbonyl]amino}-(dimethoxyphosphoryl)acetate (101.5 g, 0.341 mol, 1.0 eq.) are dissolved in THF (800 ml) and cooled to −70° C. At −70° C., TMG (78.7 g, 0.683 mmol, 6.95 ml, 2.0 eq.) is slowly added dropwise and the mixture is then stirred at −70° C. for 4 h and subsequently at RT for 4 days. The reaction mixture is concentrated and then extracted by shaking with ethyl acetate (twice 500 ml) and water, and the combined org. phases are washed with a sat. sodium chloride solution (100 ml) and dried over sodium sulfate. After concentration the crude product is chromatographed (1.5 kg of silica gel, eluent: cyclohexane/ethyl acetate 5:1). 67 g (76% of theory) of the title compound are obtained.

Provenance & Evidence