Stille electrocyclization domino reactions

Scheme 6/1.21. Combination of a domino Heck/Stille reaction with an electrocyclization.

The shimalactones, isolated from the cultured marine fungus Emericdla vane-color, are neuritogenic natural products which contain a bicyclo[4.2.0]octa-2,4-diene core structure in combination with an oxabicyclo[2.2.1]heptane moiety [105]. The complex structure of the shimalactones represents quite a synthetic challenge, which was overcome in 2008 by Trauner and coworkers [106] in a convergent synthetic approach using a domino Stille reaction/electrocyclization. 

The biomimetic 87t/67T -electrocyclization process was also applied in several other syntheses of natural products containing a bicyclo[4.2.0]octadiene structure. Parker and Lim [107] used a domino Stille/87r/67T -electrocyclization reaction for the total synthesis of the immunosuppressants SNF4435 C (267) and D (268). Interestingly, the ratio of SNF4435 C and D found in nature (2.3 1) is close to that obtained in the synthetic approach (Scheme 14.41). This indicates that an... 

Scheme 14.40 Total synthesis of shimalactones A and B (260 and 261) by Trauner and coworkers applying a domino Stille/8n/6n-electrocyclization reaction.

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See also in sourсe #XX -- [ ]

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