Lithium hydride → 1-(Methoxycarbonyl)-1-(tert-butoxycarbonyl)cyclopent-3-ene

Participants

Reaction Conditions

Reaction Steps

Add a solution of t-butyl methylmalonate (129 g, 0.75 mol) in THF (385 mL) to a slurry of LiH (14.9 g, 1.875 mol) in THF (900 mL) and N,N-dimethylpropylene urea (DMPU, 155 g, 1.2 mol) over 30 minutes while maintaining the temperature at 0-5° C. Heat the reaction mixture to 65° C. and add a solution of cis-1,4-dichloro-2-butene (95%, 100 g, 0.8 mol, 1.08 eq) in THF (100 mL) over 5.5 hours, maintaining the temperature at 63-67° C. Stir the reaction for 4 hours at 65° C. A water/MTBE work-up of the reaction mixture yields 1-(methoxycarbonyl)-1-(tert-butoxycarbonyl)cyclopent-3-ene.

Provenance & Evidence