{(2R,3R)-3-[1-((2S,3S)-3-Allyl-1,4-dioxa-spiro[4.4]non-2-yl)-vinyl]-1,4-dioxa-spiro[4.4]non-2-yl}-methanol

((2S,3S)-3-{1-[(2R,3R)-3-(4-Methoxy-benzyloxymethyl)-1,4-dioxa-spiro[4.4]non-2-yl]-vinyl}-1,4-dioxa-spiro[4.4]non-2-yl)-acetaldehyde

(2R,3R)-2-(1-((2S,3S)-3-allyl-1,4-dioxaspiro[4.4]nonan-2-yl)vinyl)-3-(((4-methoxybenzyl)oxy)methyl)-1,4-dioxaspiro[4.4]nonane

2-((2S,3S)-3-{1-[(2R,3R)-3-(4-Methoxy-benzyloxymethyl)-1,4-dioxa-spiro[4.4]non-2-yl]-vinyl}-1,4-dioxa-spiro[4.4]non-2-yl)-ethanol

tert-butyl(2-{(2S,3S)-3-[1-((2R,3R)-3-{[(4-methoxybenzyl)oxy]methyl}-1,4-dioxaspiro[4.4]non-2-yl)vinyl]-1,4-dioxaspiro[4.4]non-2-yl}ethoxy)dimethylsilane