Two types of stereocontrol in the formation of spiro skeletons via a carbonyl ene reaction and a palladium-catalysed carbonyl allylation: a formal synthesis of (+)-perhydrohistrionicotoxin

Different stereocontrol is observed in the formation of spiro skeletons via a carbonyl ene reaction and a palladium-catalysed carbonyl allylation, and a formal synthesis of (+)-perhydrohistrionicotoxin is accomplished.