(5R,8S,9R)-6-Iodo-8,9-bis-methoxymethoxy-1,3-dioxa-spiro[4.4]non-6-en-2-one

(5R,8S,9R)-8,9-Bis-(tert-butyl-dimethyl-silanyloxy)-6-iodo-1,3-dioxa-spiro[4.4]non-6-en-2-one

(5R,8S,9R)-8,9-Bis-(tert-butyl-dimethyl-silanyloxy)-6-iodo-2,2-dimethyl-1,3-dioxa-spiro[4.4]non-6-ene

(R)-3-tert-Butoxycarbonylamino-3-[6-chloro-5-((5R,6R,7S)-6-hydroxy-9-iodo-2,2-dimethyl-1,3-dioxa-spiro[4.4]non-8-en-7-yloxy)-pyridin-2-yl]-propionic acid methyl ester

3-tert-butoxycarbonylamino-3-{5-[6-(tert-butyl-dimethyl-silanyloxy)-9-iodo-2,2-dimethyl-1,3-dioxa-spiro[4.4]non-8-en-7-yloxy]-6-chloro-pyridin-2-yl}-propionic acid 3-ethynyl-3-hydroxy-2-methoxymethoxy-6-triethylsilanyl-hex-5-ynyl ester