434-13-9 A NOVEL CARBOXYL PROTECTING GROUP - THE CARBOXAMIDE DERIVED FROM 5,6-DIHYDROPHENANTHRIDINE -

Carboxyl groups protected as the amides derived from 5,6-dihydrophenanthridine are stable under a wide range of conditions and can be selectively deprotected by oxidation on treatment with cerium(IV) https://www.lookchem.com/CASDataBase_434-13-9.htm