(6R,7S,8S)-8-((R)-2-Hydroxy-1-methyl-ethyl)-6-methyl-1,4-dioxa-spiro[4.4]nonane-7-carboxylic acid

(3'R,3'aS,7'R,7'aS)-5',6'-Dihydroxy-3',7'-dimethyl-hexahydro-spiro[[1,3]dioxolane-2,2'-inden]-4'-one

(1S,2R,5S)-5-[(R)-2-(tert-Butyl-dimethyl-silanyloxy)-1-methyl-ethyl]-2-methyl-3-oxo-cyclopentanecarboxylic acid methyl ester

(1S,2R,3S,5S)-5-[(R)-2-(tert-Butyl-dimethyl-silanyloxy)-1-methyl-ethyl]-3-hydroxy-2-methyl-cyclopentanecarboxylic acid methyl ester