The reaction of butyrospermol with hydrogen chloride has been investigated. Butyrospermol has been shown to possess a typical, triterpenoid Ring A and to be a member of the group of triterpenes typified by euphol. The reaction of euphol with hydrogen chloride has also been investigated and compared with that of butyrospermol. The chemistry of isoeuphenyl acetate has been studied and a complete structure for euphol has been proposed. The tetracyclic triterpenes have been classified into two groups, on the basis of spectroscopic and molecular rotation evidence.