(4R,5R,6S)-6,7-Bis-(tert-butyl-dimethyl-silanyloxy)-2,2,4-trimethyl-1,3-dioxa-spiro[4.4]non-7-ene

(1S,2S,4S,5R,7R,8R)-2-[(E)-2-(Dimethyl-phenyl-silanyl)-vinyl]-8-(4-methoxy-benzyloxymethyl)-7-((4R,5R)-2,2,5-trimethyl-[1,3]dioxolan-4-yl)-bicyclo[2.2.2]octane-2,5-diol

(1S,2S,4R,7R,8R)-2-[(E)-2-(Dimethyl-phenyl-silanyl)-vinyl]-8-(4-methoxy-benzyloxymethyl)-7-((4R,5R)-2,2,5-trimethyl-[1,3]dioxolan-4-yl)-bicyclo[2.2.2]oct-5-en-2-ol

Acetic acid (4R,5S)-2,2,4-trimethyl-1,3-dioxa-spiro[4.4]non-6-en-7-ylmethyl ester

(4R,5R,6S)-6-(tert-Butyl-dimethyl-silanyloxy)-2,2,4-trimethyl-1,3-dioxa-spiro[4.4]non-8-en-7-one