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

(1S,2R,5S)-5-((R)-2-Hydroxy-1-methyl-ethyl)-2-methyl-3-oxo-cyclopentanecarboxylic acid methyl ester

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

(1S,5S)-5-((R)-2-Hydroxy-1-methyl-ethyl)-2-methyl-cyclopent-2-enecarboxylic acid ethyl ester

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