Disclosed are chemical entities that inhibit Uba6, each of which is a compound of Formula (I) or a pharmaceutically acceptable salt thereof, wherein R*1 is —H or —CH3; and Y is Formula (II) or Formula (III), wherein R2 is —H, —CH3 or C1-4 alkyloxycarbonyl; and RS7.1, RS7.2 and RS8.1 are defined herein; pharmaceutical compositions comprising the chemical entities; and methods of using the chemical entities. These chemical entities are useful for treating disorders, particularly cell proliferation disorders, including cancers.