(2S,6R,8S,10S)-2,8-Bis-(2-benzyloxy-ethyl)-10-hydroxy-1,7-dioxa-spiro[5.5]undecan-4-one

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

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

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