ENANTIOSELECTIVE SYNTHESIS OF 3-AZABICYCLO[4.3.0]NONANE ALKALOIDS

The stereospecific synthesis of the monoterpene alkaloids (-)-alpha-sk ytanthine ((-)-2), (-)-N-demethyl-delta-sky-tanthine ((-)-7), and (+)- epidihydrotecomanine (+)-4 was achieved from a common intermediate 22, which in turn was obtained from )-2-(1'-phenylethyl)-2-azabicyclo[2.2 .1]hept-5-ene (10), via a ketene aza-Claisen rearrangement. The piperi dine derivative (+)-31, formally the aza-analogue of (+)-isoiridomyrme cin, was also obtained from the same intermediate 22.