(3aR,4aS,5R,7aR,7bR)-7a-Acetoxymethyl-6-(2,2-dimethyl-propionyloxy)-5-methoxy-2,2-dimethyl-4a,5,7a,7b-tetrahydro-3aH-cyclopenta[4,5]furo[2,3-d][1,3]dioxole-7-carboxylic acid methyl ester

(3R,4S,5R)-5-Acetoxymethyl-5-(bis-ethylsulfanyl-methyl)-2-(2,2-dimethyl-propionyloxy)-4-hydroxy-3-methoxy-cyclopent-1-enecarboxylic acid methyl ester

(3R,4S,5S)-5-Acetoxymethyl-4-(tert-butyl-dimethyl-silanyloxy)-3-methoxy-2-methoxymethoxy-5-methyl-cyclopent-1-enecarboxylic acid methyl ester

(3R,4S,5S)-5-Acetoxymethyl-4-(tert-butyl-dimethyl-silanyloxy)-2-(2,2-dimethyl-propionyloxy)-3-methoxy-5-methyl-cyclopent-1-enecarboxylic acid methyl ester

2,2-Dimethyl-propionic acid 2-{(3aR,5S,6R,6aR)-5-[(S)-2-(2,2-dimethyl-propionyloxy)-1-methoxy-ethyl]-2,2-dimethyl-6-vinyl-tetrahydro-furo[2,3-d][1,3]dioxol-6-yl}-ethyl ester