Cyclization of Polyenes. III Cyclization of Squalene-oxides

Abstract

For the purpose of finding the optimum conditions of biogenetic-type synthesis of onocerin from squalene 2, 3; 22, 23-dioxide (IV), acid-catalyzed cyclization (BF₃-etherate in water-saturated benzene) of squalene-2, 3-oxide (I) was investigated to afford the compounds, III, V, VI, VII, VIII and IX. The gross structure of these compounds was established by physical and chemical evidences. The cyclization of IV was also tried.