Retinyl isocyanide

In a variation of the Wittig reaction, the a-metallized retinyl isocyanide (98) was reacted with retinaldehyde (2) to give P-carotene via an unstable oxazoline intermediate (Schollkopf, 1977). 

The formamide (587a) was reacted with thionyl chloride, and the reaction mixture was then worked up under basic conditions to give (all- )-retinyl isocyanide (588), which was employed as an intermediate for the synthesis of p-carotene (Kienzle, 1973b). 

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