10.1021/ja00034a036
The research details the total synthesis of latrunculins A and B, two architecturally novel toxins isolated from the Red Sea sponge Latrunculia magnifica. The study presents highly convergent and stereocontrolled routes to achieve these syntheses, with the longest linear sequences being 16 and 12 steps, respectively. Key chemicals and strategies involved in the synthesis include the aldol reaction of aldehyde (-)-12 with methyl ketone (-)-13, an acid-catalyzed reorganization-equilibration of ortho ester (-)-11, and a Mitsunobu macrolide cyclization. The synthesis also involves the preparation of various intermediates such as aldehyde (-)-12 derived from (f)-2-allylcyclopentanone and (+)-(R,R)-2,3-butanediol, and ketone (-)-13 derived from L-cysteine ethyl ester. The research highlights the challenges and solutions in achieving the correct stereochemistry and configuration of the target compounds, showcasing the importance of protecting group strategies and selective reagents like lithium bis(trimethylsilyl)amide and dibutylboron triflate. The successful synthesis of latrunculins A and B provides valuable insights into the structure and function of these toxins, which have significant biological profiles and potential applications in studying actin microfilament structure and function.