Patchoulanes and Seychellanes

A biogenetic-like cyclization of a-bulnesol (71) to p-patchoulene (180) occurs to the extent of -- 30% in sulfuric acid-acetic acid, along with simple dehydration and subsequent double bond isomerizations to various bulnesenes and guaienes (263). A more efficient cyclization to (180) (60%) is observed when bulnesol is heated with pyridine and alu- 

Cycloseychellene (187) is a new seychellane sesquiterpene which co-occurs with seychellene (183) (269). An acid catalyzed equilibration between these two compounds has been achieved by reaction of either isomer wich cupric acetate in acetic acid, the equilibrium favoring seychellene (269). 

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