Methanesulfonic acid (1S,2S)-2-benzyloxy-1-(tert-butyl-diphenyl-silanyloxymethyl)-4,4-bis-ethylsulfanyl-butyl ester

(S)-5-((S)-2,2-Dimethyl-[1,3]dioxolan-4-yl)-5-ethoxycarbonyloxy-pentanoic acid ethyl ester