Cyclopropanation reactions on -cis-himachalene and a -himachalene

The crystallographic structures of 3,4-dibromomethano-3,5,5-trimethyldecahydro-1H-benzocycloheptene-9,1^'-spiro(2^',2^'-dibromocyclopropane), C₁₇H₂₄Br₄, (3), 3,4-dichloromethano-3,5,5-trimethyldecahydro-1H-benzocycloheptene-9,1^'-spiro(2^',2^'-dichlorocyclopropane), C₁₇H₂₄Cl₄, (4), and 9,9a-dichloromethano-3,5,5,9-tetramethyl-1,4a,5,6,7,8,9,9a-octahydro-2H-benzocycloheptene, C₁₆H₂₄Cl₂, (5), resulting from cyclopropanation reactions of the C=C double bonds of -cis-himachalene and -himachalene, are reported.