(1R*,2'R*,4R*,8R*)-8-methyl-3-oxabicyclo<3.3.0>octa-2,7-dione-1-spiro-1'-(4'-methyl-2'-(trimethylsiloxy)-3'-cyclohexene)

2-methyl-2-<1-(methoxycarbonyl)ethen-1-yl>-1,3-cyclopentanedione

(1S*,2R*,6R*,7R*,11S*)-6-hydroxy-2-methyl-1-(methoxycarbonyl)-8-methylene-3-oxo-11-(trimethylsiloxy)tricyclo<5.3.1.02,6>undecane

3-Chloro-2-(1-methyl-2,5-dioxo-cyclopentyl)-propionic acid methyl ester

(1S*,4S*,7R*,8R*,12S*,13S*)-7-hydroxy-12-methyl-9-methylene-13-(trimethylsiloxy)-3-oxatetracyclo<5.4.1.1.1,8.04,12>tridecan-2-one