Elkin, Pavel K.; Levin, Vitalij V.; Dilman, Alexander D.; Struchkova, Marina I.; Belyakov, Pavel A.; Arkhipov, Dmitry E.; Korlyukov, Alexander A.; Tartakovsky, Vladimir A. Tetrahedron Letters, 2011 , vol. 52, # 41 p. 5259 - 5263