Abstract: Compounds having the formula ##STR1## wherein R.sub.1 and R.sub.2 are lower alkyl or together lower alkylene,R.sub.3 is hydrogen, alkyl, methoxyethyl, alkenyl, propargyl, benzyl, alkyl substituted benzyl, or acyl,R.sub.4 is alkylene of 1 to 4 carbon atoms substituted with alkyl or alkenyl of 1 to 18 carbon atoms, alkenylene of 1 to 4 carbon atoms, cycloalkylene, cycloalkenylene, bicycloalkylene, bicycloalkenylene, or phenylene,M is hydrogen or a metal, andz has a value of from 1 to 4, and either (a) R.sub.5 is alkyl of 1 to 6 carbon atoms, R.sub.6 is alkyl of 1 to 6 carbon atoms, and R.sub.7 and R.sub.8 are independently hydrogen or alkyl of 1 to 5 carbon atoms, provided that R.sub.7 and R.sub.8 are not both hydrogen, or (b) R.sub.5 and R.sub.6 are together lower alkylene and R.sub.7 and R.sub.8 are independently hydrogen or alkyl of 1 to 5 carbon atoms,are good light stabilizers.