Patent ID: 7429670

Claim:
A compound having the structure: wherein R is H or -A-Ar, where A is an alkyl group; and Ar is an aryl group, which may contain heteroatoms and may be unsubstituted or substituted by one to five substituents each selected from the group consisting of alkoxy, —CH 2 CO 2 R 4 , and —CH 2 CONR 5 R 6 ; where R 4 is an alkyl group; and R 5 and R 6 are each, independently, hydrogen or a branched or unbranched alkyl group; wherein R 1 is H, —CONC 5 H 10 , —CONC 4 H 8 O or —COR 7 , where R 7 is alkyl, aryl or —NR 5 ′R 6 ′; where R 5 ′ and R 6 ′ are each, independently, hydrogen, methyl, or t-butyl; wherein R 2 is present or absent, and when present is benzoyl, —CO 2 C 6 H 4 NO 2 , —CONHMe, —CONHtBu, —CONC 5 H 10 , —CONC 4 H 8 O, —CONR 5 R 6 or —CO-phenyl which phenyl is substituted, where R 5 and R 6 are each, independently, hydrogen, methyl, t-butyl, or —CO—Z-R 8 where R 8 is alkyl, or aryl; and Z is oxygen; or R 2 is H and R 1 is H, and R is p-methoxybenzyl, or picolyl, or R 2 is H and R 1 is —C(O)NHt-Bu, or —C(O)NHMe, and R is H, wherein R 3 is present or absent, and when present is —COR 9 ; where R 9 is alkyl or aryl; wherein only one of R 2 or R 3 is present in the compound; wherein only two of R, R 1 , R 2 and R 3 are H; and wherein each of a and b designates a single covalent bond which is present or absent, where bond a is present when R 3 is absent and bond b is present when R 2 is absent; or an optically pure enantiomer or a pharmaceutically acceptable salt of the compound.