7-(2'-chloroethyl)-3aR-ethyl-7aS-hexahydroindene-1,6-dione

4-(2'-chloroethyl)-7aR-ethyl-1,2,3,6,7,7a-hexahydroinden-5-one

(3aR,7aS)-7-(2-Azido-ethyl)-3a-ethyl-hexahydro-indene-1,6-dione

(R)-7a'-ethyl-2',6',7',7a'-tetrahydrospiro[cyclopropane-1,4'-inden]-5'(1'H)-one