While the previously used displacement reaction of sodim 1-adamantyl oxide on 4-fluoronitrobenzene was applicable to the preparation of 4-(1-adamantyloxy)aniline and several related compounds, certain derivatives were not easily accessible by this route. Thus the recently reported ortho alkylation of anilines and the dicyclohexylcarbodiimide-promoted coupling of 1-adamantanol with phenols were useful in the preparation of aromatic-substituted derivatives. Furthermore, addition of phenylmagnesium bromide to 1-cyanoadamantane provided entry to the 4-(1-adamantylmethyl)aniline series. 4-(1-Adamantyloxy)aniline (3) is herein reported to be a more potent hypobetalipoproteinemic agent than the previously reported bicyclooctyloxy analogue. Replacement of the oxygen atom of 3 with sulfur (74) or methylene (62), but not nitrogen (71), results in active compounds. In the oxygen series derived from 3, the widest scope of substitution on nitrogen resulting in activity is found. The N-ethoxycarbonyl (5), acetyl (6), methyl (12), ethyl (13), N-methyl-N-(2-hydroxyethyl) (19), N-methyl-N-formyl (22), N,N-dimethyl (26), pyrrolidine (14), and piperidine (15) derivatives are active. Aromatic ring substitution also provided the active 3-chloro (44b), 2-fluoro (41b, 42, and 43), and 2-methylthiomethyl (48) compounds. Thus these active compounds are identified for further development as hypobetalipoproteinemic agents.