[(2R,4S,6S,8S,10S)-10-Methyl-8-((R)-3-methyl-2-methylene-4-oxo-butyl)-4,10-bis-triethylsilanyloxy-1,7-dioxa-spiro[5.5]undec-2-yl]-acetic acid tert-butyl ester

(2S,4S,6R,8S,10S)-10-(tert-Butyl-dimethyl-silanyloxy)-8-(2-hydroxy-ethyl)-4-methyl-2-(2-triethylsilanyloxy-ethyl)-1,7-dioxa-spiro[5.5]undecan-4-ol

[(2R,4S,6S,8S,10S)-10-Methyl-8-((R)-3-methyl-2-methylene-4-triethylsilanyloxy-butyl)-4,10-bis-triethylsilanyloxy-1,7-dioxa-spiro[5.5]undec-2-yl]-acetic acid tert-butyl ester

[(2R,4S,6S,8S,10S)-4-(tert-Butyl-dimethyl-silanyloxy)-10-hydroxy-10-methyl-8-(2-triethylsilanyloxy-ethyl)-1,7-dioxa-spiro[5.5]undec-2-yl]-acetaldehyde

[(2R,4S,6S,8S,10S)-8-[(2S,3R)-4-((R)-4-Benzyl-2-oxo-oxazolidin-3-yl)-2-hydroxy-3-methyl-4-oxo-butyl]-4-(tert-butyl-dimethyl-silanyloxy)-10-hydroxy-10-methyl-1,7-dioxa-spiro[5.5]undec-2-yl]-acetic acid tert-butyl ester

(2S,6S,8S)-2,8-Bis-(2-benzyloxy-ethyl)-10-triisopropylsilanyloxy-1,7-dioxa-spiro[5.5]undec-10-en-4-one

[(2R,4S,6S,8S,10S)-4-(tert-Butyl-dimethyl-silanyloxy)-8-((2S,3S)-2,4-dihydroxy-3-methyl-butyl)-10-hydroxy-10-methyl-1,7-dioxa-spiro[5.5]undec-2-yl]-acetic acid tert-butyl ester