Cyclopropenones (I) react with NaCN in solvents exhibiting nucleophilic properties to furnish novel 3-cyanopropionic acid derivatives in moderate to good yields and anti-diastereoselectivity. -(SKORNYAKOV*, Y. V.; TERESHCHENKO, D. S.; IGNATENKO, A. V.; PROSKURNINA, M. V.; ZEFIROV, N. S.; Russ. Chem. Bull. 54 (2005) 9, 2129-2132; Dep. Chem., Lomonosov Moscow State Univ., Moscow 119992, Russia; Eng.) -C. Hettrich