Wittig reactions highest yields

Further reaction of 86 with the Cio-dialdehyde 58 is carried out in boiling ethanol with ethyloxirane as HCI acceptor (Scheme 29). Thermal (Z -> )-isomerization and crystallization occur simultaneously during this reaction. After recrystallization by chloroform -> ethanol solvent exchange, the desired product 119 is obtained in 93% yield, the highest yield obtained in a Wittig olefination of the C15 + Cio + C15 = C40 type. 

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