An unprecedented straightforward synthesis of chiral pyrrolo[3,4- b ]quinolone and Pyrrolo[3,2-b]quinolone backbones starting from trans-4-hydroxy-L-proline

The straightforward synthesis of pyrrolo[3,4-b]quinolone and pyrrolo[3,2-b]quinolone backbones,which can be found in molecules exhibiting anticancer activities,is presented. the key step of the process is an efficient and unprecedented friedländer condensation between an oxoproline carbamate,obtained in 3 steps and good yield starting from commercially available and relatively cheap trans-4-hydroxy-l-proline,and various 2-amino-substituted carbonyl derivatives. it was demonstrated that the formation of the two possible regioisomers was fully triggered by both the r substituent onto the 2-amino-substituted carbonyl compounds and the ester function onto the oxoproline carbamate. thus,in some cases,a complete regiocontrol for the friedländer reaction could be attained. © 2016 sébastien comesse and adam daïch.