PHOTOCHEMICAL-TRANSFORMATIONS OF PROTEINOGENIC AND NON-PROTEINOGENIC AMINO-ACIDS

The photochemistry of N-activated enantiomerically pure alpha-amino ac ids is described with emphasis on chemo-, regio-, stereo-, and spin se lectivity. An especially valuable chromophore is the phthalimido group . The first excited singlet stares are short-lived and deactivated (ch emically) via homolytic CPI cleavage or (physically) via electron-tran sfer steps. The first excited tripler states are chemically deactivate d via electron-transfer reactions and subsequent deprotonation/couplin g steps. A wide variety of product types were synthesized, and potenti al target molecules were available by tuning the reaction conditions. Also remote groups can be activated by means of electron-transfer step s, which represents an attractive new synthetic protocol for macrocycl ization.