1. Institute of Organic Chemistry and Biochemistry; The Czech Academy of Sciences, Flemingovo nám. 542/2; 116 10 Prague Czech Republic
2. Institute of Chemistry, Faculty of Natural Sciences; Comenius University, Ilkovičova 6; Bratislava 842 15 Slovakia
3. Department of Organic Chemistry, Faculty of Science; Charles University, Hlavova 2030/8; 128 43 Prague Czech Republic