Enantioselective Synthesis of ( R )‐ N ‐Boc‐1‐amino‐2‐arylcyclopropene‐1‐carboxylic Acid Methyl Ester

The addition of a bislactim ether carbene to an arylethyne is the key step in the synthesis of the title compounds 1 . cyclo ‐( L ‐Val‐Gly) 2 , used as lactim ether, furnishes the target molecules ( R )‐ 1 in almost enantiomerically pure form, while ent ‐ 2 correspondingly furnishes the ( S )‐isomers. Compounds of the type 1 should be very effective suicide‐inhibitors for pyridoxalphosphate‐dependent enzymes (RH, CH 3 , Cl).