ENANTIOPURE BUILDING BLOCKS FOR MARINE NATURAL PRODUCTS VIA DIFFERENTIATION OF ENANTIOTOPIC GROUPS

Abstract The group and face-selective cycloaddition of the enantiopure cyclopentadiene 4 to the tyrosine-related spirocylohexadienone 10 provided a high yield of the enantiomerically pure cyclohexadienone 11 . Stereoselective transformations at the remaining double bond followed by a thermal retro-process, finally giving rise to the chromophore of the marine agelorin antibioticcs isolated from the sponge Agelas oroides Schmidt.