A Simple, Mild and Straight forward Route for the Synthesis of α‐Ureidopeptidomimetics Using Cbz‐Protected Amino Acid Esters

New efficient synthesis of tRNA related adenosines bearing the hydantoin ring (ct6A, ms2ct6A) by intramolecular cyclization of N6-(N-Boc-α-aminoacyl)-adenosine derivatives

A novel and efficient way for synthesis of N6-hydantoin modified adenosines, which utilizes readily available N6-(N-Boc-α-aminoacyl)-adenosine derivatives, was developed. The procedure is based on the epimerization free Tf2O-mediated conversion of the Boc group into an isocyanate moiety, followed by intramolecular cyclization. Using this method two recently discovered hydantoin modified tRNA adenosines, i.e. cyclic N6-threonylcarbamoyl-adenosine (ct6A) and 2-methylthio-N6-threonylcarbamoyladenosine (ms2ct6A) were prepared in good yields.

Simple and efficient synthesis of bicyclic enol-carbamates: access to brabantamides and their analogues

A simple and short synthesis of bicyclic enol-carbamates with high E/Z selectivity and the synthesis of brabantamide A analogue are presented.