The Aromatisation Reaction of Δ^{7, 9 (11)}-Triterpenoids

Abstract

The "anthrasteroid"-type rearrangement of bauera-7, 9 (11)-dienyl acetate (1) was reexamined and the product was proved not to be 2 but to be expressed by 6. The aromatisation reaction was applied for 7, 9 (11)-dienes (13, 14, 15, 16) of tirucallane, lanostane, fernane, and arborane series and the same type of hydrocarbons (17, 18, 19, 20) were obtained in good yields.