pi-Facial selectivities of diastereotopic ketones: p-bromobenzoates of 4-hetero-1-decalinols

The crystal structures of the p-bromobenzoates of cis-4-oxa-1-decalinyl (C1 6H19BrO3), trans-4-oxa-1-decalinyl (C16H19BrO3), N-benzyl-cis-4-aza-1-decal inyl (C23H26BrNO2), N-benzyl-trans-4-aza-1-decalinyl (C23H26BrNO2) and tran s-4-thia-1-decalinyl (C16H19BrO2S) (decalin is perhydronaphthalene) have be en determined as part of a study directed at predicting and interpreting th e pi -facial selectivities of diastereotopic ketones in reactions with nucl eophiles. All five structures are composed of molecules that are separated by normal van der Waals distances. In all five structures, the heterocyclic and cyclohexyl rings adopt chair conformations, and the p-bromobenzoate gr oups are planar.