Electrophilic cyclization of an allylsilane derived from geraniol to give karahanaenol is reported and its biosynthetic implication is discussed. ... In 1955, polyolefinic electrophilic cyclization was proposed as the biogenetic pathway leading to cyclic isoprenoid natural products.1.2 Since then, many studies have been carried out to apply this cyclization to the synthesis of six-membered rings [(l)] of terpenes and steroids.3 The extension of the electro- philic cyclization ...
