(2S,3S,4S)-1-(tert-butyloxycarbonyl)-2-<<(tert-butyldimethylsilyl)oxy>methyl>-3-<2-<<(tert-butyloxy)dimethylsilyl>oxy>ethyl>-4-<1-(hydroxymethyl)ethenyl>pyrrolidine

(2S,3S,4S)-3-[2-(tert-Butyl-dimethyl-silanyloxy)-ethyl]-2-(tert-butyl-dimethyl-silanyloxymethyl)-4-((Z)-1-formyl-buta-1,3-dienyl)-pyrrolidine-1-carboxylic acid tert-butyl ester