Synonyms: Dispiro[oxirane-2,2'-[2H]naphth[2',1':4,5]indeno[2,1-b]furan-8'(1'H),2''-[2H]pyran],spiro[oxirane-2,3'-spirostan] deriv.; Dispiro[oxirane-2,2'-[2H]naphth[2',1':4,5]indeno[2,1-b]furan-8'(1'H),2''-[2H]pyran],eicosahydro-4'a,5'',6'a,7'-tetramethyl-, [4'aS-(4'aa,4'bb,6'aa,6'bb,7'b,8'b,9'ab,10'ab,10'ba)]-; [4'aS-(4'aa,4'bb,6'aa,6'bb,7'b,8'b,9'ab,10'ab,10'ba)]-Eicosahydro-4'a,5'',6'a,7'-tetramethyldispiro[oxirane-2,2'-[2H]naphth[2',1':4,5]indeno[2,1-b]furan-8'(1'H),2''-[2H]pyran]