Huperzine A is a new alkaloid isolated from the club moss Huperzia serrata (Thunb.) Trev., a Chinese folk medicine. This alkaloid exhibits potent activity as an inhibitor of acetylcholinesterase. Consequently, the compound is presently being investigated in China for the treatment of individuals suffering from various forms various forms of memory impairment including Alzheimer's dementia. Details of the total synthesis of (±)-huperzine A are described as well as the preparation of a variety of huperzine analogues including its presumed pharmacophore. The extent of these new compounds to inhibit acetylcholinesterase is presented along with a discussion of the effects of the structural changes on biological activity