AN OXIDATIVE INTRAMOLECULAR PHENOLIC COUPLING REACTION FOR THE SYNTHESIS OF AMARYLLIDACEAE ALKALOIDS USING A HYPERVALENT IODINE(III) REAGENT

The oxidative intramolecular phenolic coupling reaction of norbelladin e derivatives (1) was investigated with the aim of preparing amaryllid aceae alkaloids. Spirodienone compounds (2), which are intermediates f or the synthesis of an amaryllidaceae alkaloid, (+)-maritidine, or phe nol ether derivatives containing the 5,6,7,8-tetrahydrobenzazocine sys tems (9), were selectively obtained by the reaction of 1 and the hyper valent iodine(III) reagent, phenyliodine(III) bis(trifluoroacetate) (P IFA). Both p-p' coupling (11) and p-o' coupling spirodienone compounds (12) were obtained by the reaction of phenol derivatives having an al koxy group at the C-3' position (10) with PIFA.