The use of nitrones in the synthesis of anatoxin-a, very fast death factor

Article abstract of DOI:10.1016/S0040-4020(01)96699-2

The synthesis of anatoxin-a (1) was completed by using the cycloaddition of 1-pyrroline-1-oxide (2) onto dienol (6), a reaction which proceeded with high stereoselectivity, regioselectivity, and site selectivity. The resultant adduct (i.e. 7) was oxidized to a second nitrone (i.e. 8) which undergoes a second closure to afford cycloadduct 9a with regiospecificity. The conversion of 9a into anatoxin-a hydrochloride (1 · HCl) was both direct and efficient.