Schlosser modified Wittig reaction

The asymmetric total synthesis of ISP-I (myriocin, thermozymocidin) was accomplished by utilizing the Schlosser modified Wittig reaction as one of the key steps in the laboratory of Y. Nagao. The phosphonium bromide fragment was treated with PhLi at 0 °C to generate the phosphorous ylide which was reacted with the aldehyde at -78 °C. The resulting mixture of lithiobetaines was treated with PhLi at 0 °C to afford the desired ( j-alkene with excellent stereoselectivity. 

Scheme 5.1 depicts a typical representation of the Wittig reaction, which is one of the most commonly used olefin preparation reactions [1]. The reaction was developed by Georg Wittig, who was a Nobel Prize laureate in 1979. The control of dia-stereochemistry in the product has been studied in detail by Schlosser. Both the E and Z diastereomers can be obtained with excellent selectivity by means of Schlosser s modified method [2]. 

---