(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)

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

(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

rac-(1R,2R,3a'R,6a'R)-5'-bromo-3a',4-dimethyl-2-((trimethylsilyl)oxy)-3a',5',6',6a'-tetrahydro-2'H,4'H-spiro[cyclohexane-1,3'-cyclopenta[b]furan]-3-ene-2',4'-dione