Carfilzomib Impurity 65

(R)-t-Butyl (2,6-Dimethyl-3-oxohept-1-en-4-yl)carbamate is an intermediate in synthesizing (R)-2-Amino-4-methyl-1-((S)-2-methyloxiran-2-yl)pentan-1-one Trifluoroacetate Salt (A605100), an impurity of carfilzomib (C183460). Carfilzomib is a second-generation proteasome inhibitor that is used as a treatment in relapsed and refractory multiple myeloma.