The acid-catalyzedisomerization of 24-methylenecycloartanol with sulfuric acid afforded cyclosadol (23E-Δ23), isocyclosadol (23Z-Δ23), and other isomers, including lanostane- and cucurbitane-type isomers with (23E)- and (23Z)-Δ23- and Δ24-unsaturated side chains. The phytochemical significance of the isomers is discussed.