e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
Conversion of dipeptides and a tetrapeptide to macrocyclic ionophores by means of caesium aided ring closure of the N-2-chloroacetyl derivatives
…, L Leegstra, E Rokaszewski, G Gruppen…
Index: Kruizinga, Wim H.; Kingma, Rob; Leegstra, Libbe; Rokaszewski, Edward; Gruppen, Gert; Kellogg, Richard M. Journal of the Chemical Society, Chemical Communications, 1990 , # 22 p. 1647 - 1648
Three di-,(Gly) 2,(Val) 2 and (Leu) 2, and one tetra-peptide,(Gly) 4, have been acylated with 2-chloroacetyl chloride and the resulting products treated with Cs2CO3 in dimethylformamide (DMF) solution;(Gly) 2 and (Leu) 4 provided strained 9-membered rings whereas (Val) 2 dimerized to the 18-membered ring.