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Quantum yields were measured by using a "linear optical bench" system described earlier2 and employing a filter solution combination with three 1-cm compartments containing separately 2.0 M (252.72 g/L) nickel sulfate hexahydrate in 5% sulfuric acid, 0.8 M (224.88 g/L) cobalt sulfate heptahydrate in 5% sulfuric acid, and 0.0012 (0.378 g/L) bismuth chloride in 2:3 hydrochloric acid/water. The UV transmission of this filter system was 240-310 nm with a maximum at 275 nm. Product analyses for the spirocyclicamine 30 was performed by HPLC (Partisil M-9 10/50). Conversions were in the range of 1.7-1.9%.

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Ecklonialactones A, B, and E, previously isolated from the brown alga Ecklonia stolonifera, have been isolated from the Oregon phaeophyte Egregia menziesii. The structure and relative stereochemistry of ecklonialactone E were independently determined by various nmr techniques. The absolute stereochemistry of ecklonialactone A was deduced by cd analysis of a dibenzoate derivative, which indicated it possessed a 11S, 12R, 13S, 15R, 16S stereochemistry. Similar 1H- and 13C-nmr data and optical rotations for all of the ecklonialactones indicate that B and E have the same stereochemistry as A at comparable stereocenters.