(6R,8R,10R)-8-benzyloxymethyl-10-(tert-butyl-dimethyl-silanyloxy)-2-(2-hydroxy-butyl)-1,7-dioxa-spiro[5.5]undec-2-en-4-one

2,2-dimethyl-propionic acid-(2R,4R,6R)-4-(tert-butyl-dimethyl-silanyloxy)-8-(2-hydroxy-butyl)-10-oxo-1,7-dioxa-spiro[5.5]undec-8-en-2-ylmethyl ester

2-[(4R)-5-benzyloxy-2-(tert-butyl-dimethyl-silanyloxy)-4-(4-methoxy-benzyloxy)-pentyl]-6-methyl-pyran-4-one

2,2-dimethyl-propionic acid-(2S,4R,6S,8R,10S)-8-(2-acetoxy-butyl)-4-hydroxy-10-methoxy-1,7-dioxa-spiro[5.5]undec-2-ylmethyl ester

2,2-dimethyl-propionic acid-(2R,4R,6S,8R)-4-(tert-butyl-dimethyl-silanyloxy)-8-(2-hydroxy-butyl)-10-oxo-1,7-dioxa-spiro[5.5]undec-2-ylmethyl ester