[(1S,2S,3S,4S,6R)-1-Benzyloxy-4-(tert-butyl-dimethyl-silanyloxy)-3-(2,2-dimethoxy-ethyl)-3-methyl-7-oxa-bicyclo[4.2.0]oct-2-yl]-acetic acid methyl ester

(2aR,4S,4aS,8aS,8bS)-4-((tert-butyldimethylsilyl)oxy)-4a-methyloctahydrospiro[naphtho[2,1-b]oxete-7,2'-[1,3]dioxolan]-8b(1H)-ol

[(1S,2S,3S,4S,6R)-1-Benzyloxy-4-(tert-butyl-dimethyl-silanyloxy)-3-methyl-3-(2-oxo-ethyl)-7-oxa-bicyclo[4.2.0]oct-2-yl]-acetic acid methyl ester

(2aR,4S,4aS,6R,8aS,8bS)-8b-Benzyloxy-4-(tert-butyl-dimethyl-silanyloxy)-6-hydroxy-4a-methyl-octahydro-2-oxa-cyclobuta[a]naphthalen-7-one

(2aR,4S,4aS,8aS,8bS)-8b-Benzyloxy-4-(tert-butyl-dimethyl-silanyloxy)-4a-methyl-octahydro-2-oxa-cyclobuta[a]naphthalen-7-one