2,2-Dimethyl-propionic acid (S)-4-[(3R,4S)-3-(tert-butyl-diphenyl-silanyloxy)-4-(4-methoxy-benzyloxy)-5-oxo-cyclopent-1-enyl]-2-(R)-1,4-dioxa-spiro[4.4]non-2-yl-2-triethylsilanyloxy-but-3-ynyl ester

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

(5R,6R,7S)-9-Iodo-2,2-dimethyl-1,3-dioxa-spiro[4.4]non-8-ene-6,7-diol