Isotactic polymethoxy 1-alkenes from blue-green algae. Synthesis and absolute stereochemistry
摘要:
Novel isotactic polymethoxy-1-alkenes 1-4 were isolated from tolytoxin-producing blue-green algae belonging to the family Scytonemataceae. Scytonema mirabile produced 1 and 2, whereas 3 and 4 were isolated from S. burmanicum. The gross structures and relative stereochemistries were determined by mass and NMR spectral analyses. The absolute configurations of 1-4 were established by direct comparison with optically active synthetic samples.
Total synthesis of natural products having 1,3- -polyol, δ-lactone of (2 ,5 ,7 ,9 ,11 )-tetrahydroxyhexacos-2-enoic acid and 4,6,8,10,12,14,16,18,20-all- -nonamethoxy-1-pentacosene