N-Ylide Mediated Synthesis and Resolution of a Chiral Pyrimidinyl Cyclopropane Carboxylic Acid

We report the synthesis of a pyrimidinyl trans-cyclopropane carboxylic acid (rac-1) in 3 steps (58% yield) from 2-chloro-4-methylpyrimidine (2), and its chiral resolution via recrystallization of the (S)-1-(1-naphthyl)ethylamine or (+)-abietylamine salts. Following the observation of a palladium-catalyzed conjugate addition of potassium vinyltrifluoroborate to 4-methyl-2-vinylpyrimidine (3), an efficient, novel cyclopropanation of 3 was developed through reaction with the nitrogen ylide derived from t-butyl bromoacetate and DABCO.