(2R,3R,5S,8R,10S)-2-((1R,3R)-5-Acetoxy-3-methyl-1-triethylsilanyloxy-pentyl)-8,10-dimethyl-3-triethylsilanyloxy-1-oxa-6-aza-spiro[4.5]decane-6-carboxylic acid tert-butyl ester

(2R,3R,5S,8R,10S)-2-((1R,3R)-5-Hydroxy-3,7-dimethyl-1-triethylsilanyloxy-oct-7-enyl)-8,10-dimethyl-3-triethylsilanyloxy-1-oxa-6-aza-spiro[4.5]decane-6-carboxylic acid tert-butyl ester