Efficient Synthesis of a Styryl Analogue of (2S,3R,4E)‐N2‐Octadecanoyl‐4‐tetradecasphingenine via Cross‐Metathesis Reaction

The first total synthesis of sphingolipid (2S,3R,4E)‐N²‐octadecanoyl‐4‐tetradecasphingenine ( 1a ), a natural sphingolipid isolated from Bombycis Corpus 101A, and of its styryl analogue 1b was achieved in good overall yield (Schemes 1 and 2). The key step involved the installation with (E) stereoselectivity of a long lipophilic chain or phenyl group on allyl alcohol derivative 3 via a cross‐metathesis reaction (→ 5a or 5b ). The N‐Boc protected 3 was easily accessible from (S)‐Garner aldehyde.