Palytoxin carboxylic acid synthesis

And so the skillful selection, introduction, and removal of a total of 12 different protective groups has played a major role in the successful total synthesis of palytoxin carboxylic acid (Figure 1,2). 

Scheme 9. Coupling of key intermediates 24 and 30 and synthesis of fully protected palytoxin carboxylic acid 31.

Scheme 10. Deprotection of 31 and synthesis of palytoxin carboxylic acid 32.

Suh, E.M., and Kishi, Y. 1994. Synthesis of palytoxin from palytoxin carboxylic acid. Journal of the American Chemical Society 116(24) 11205-11206. 

In 1989, despite the hnge number of possible stereoisomers, a research group led by Professor Kishi managed to achieve the total chemical synthesis of a fully protected palytoxin carboxylic acid [7]. This was subsequently converted to palytoxin carboxylic acid and palytoxin amide without the use of protecting groups [60]. By comparison of biological activity, chromatographic behavior, and... 

In 1980, using plasma desorption mass spectrometry with californium ( Cf), the exact molecular weight of PTX (1) was established as 2680 for the first time [13]. The planar stracture of 1 was eventually clarified in 1981 [14-16], and its complete stereostructure was elucidated in 1982 [17-20]. Finally, the true stereostructure of 1 was established by an overall degradation reaction and chemical synthesis in 1982. Kishi and his coworkers completed the total synthesis of palytoxin carboxylic acid (3) in 1989 [21, 22], and of PTX itself in 1994 (Figure 30.2) [23,24]. 

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