Patent ID: 8052961

Claim:
A compound having the structure: wherein R 1a and R 1b are independently H, alkyl, F, or fluoroalkyl; wherein R 2a , R 2b , R 2a′ , and R 2b′ are independently H, alkyl, F, fluoroalkyl, aryl, or alkenyl; wherein R 3 is OH, alkoxyl, NH 2 , alkylamino, or dialkylamino; wherein R 4a and R 4b are independently H, alkyl, acyl, or alkyloxycarbonyl; wherein R 11 , R 12 , R 13 , R 21 , R 22 , and R 23 are independently H, alkyl, F, or fluoroalkyl; and wherein C0, C1, C2, and C2′ are independently chiral or achiral.