[11-(2,5-Dioxo-pyrrolidin-1-yloxycarbonyloxy)-undecyl]-phosphonic acid (3S,8S,9S,10R,13R,14S,17R)-17-((R)-1,5-dimethyl-hexyl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yl ester 4-nitro-phenyl ester

[11-(2,5-Dioxo-pyrrolidin-1-yloxycarbonyloxy)-undecyl]-phosphonic acid 12-(7-nitro-benzo[1,2,5]oxadiazol-4-ylamino)-dodecyl ester 4-nitro-phenyl ester

[11-(2,5-Dioxo-pyrrolidin-1-yloxycarbonyloxy)-undecyl]-phosphonic acid 4-nitro-phenyl ester octyl ester

[11-(2,5-Dioxo-pyrrolidin-1-yloxycarbonyloxy)-undecyl]-phosphonic acid dodecyl ester 4-nitro-phenyl ester

2-decyltetradecvyl (4-nitrophenyl) [11-([(2,5-dioxotetrahydro-1H-1-pyrrolyl)oxy]carbonyloxy)undecyl] phosphonate