Brevetoxins Wittig reaction

The Wittig reaction has been used widely in organic synthesis. For example, a number of steps in a synthesis of the neurotoxin brevetoxin B make use of the Wittig reaction with both stabilized and non-stabilized phosphonium ylides, two of which are shown in Scheme 2.74. This synthesis also uses a Wittig reaction in a later, key step to combine two large fragments using a non-stabilized phosphonium ylide to prepare a Z-alkene. 

Nicolaou also made use of the Wittig reaction in his synthesis of brevetoxin B 136. The western 133 and eastern 134 portions of the molecule were linked in 75% yield using a classical Wittig reaction to generate 135. 

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