Acyclic Thiol Prodrugs

A compound of structural Formula (I):

• or pharmaceutically acceptable salts, hydrates or solvate thereof wherein:
• R1 is the residue of a thiol of molecular weight of less than 1000 daltons;
• Y is —NR2R3;
• X is —OR4, or —SR1;
• R2 and R3 are independently —H, alkyl, substituted alkyl, alkenyl, substituted alkenyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, cycloheteroalkyl, substituted cycloheteroalkyl, cycloheteroalkenyl, substituted cycloheteroalkenyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, arylalkenyl, substituted arylalkenyl, heteroalkyl, substituted heteroalkyl, heteroalkenyl, substituted heteroalkenyl, heteroaryl, substituted heteroaryl, heteroarylalkyl, substituted heteroarylalkyl, heteroarylalkenyl, substituted heteroarylalkenyl or R2 and R3 together with the atoms to which they are attached form a cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl heterocycloalkyl, substituted heterocycloalkyl, heterocycloalkenyl or substituted heterocycloalkenyl ring;
• and
• R4 is alkyl, substituted alkyl, alkenyl, substituted alkenyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, cycloheteroalkyl, substituted cycloheteroalkyl, cycloheteroalkenyl, substituted cycloheteroalkenyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, arylalkenyl, substituted arylalkenyl, heteroalkyl, heteroalkenyl, heteroaryl, substituted heteroaryl, heteroarylalkyl, substituted heteroarylalkyl, heteroarylalkenyl or substituted heteroarylalkyl;
• provided that both R2 and R are not —H and unless R2 and R3 together with the atoms to which they are attached form a cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl heterocycloalkyl, substituted heterocycloalkyl, heterocycloalkenyl or substituted heterocycloalkenyl ring that one of R2 and R3 is —H.