Diastereoselective addition of alkenylchromium(III) reagents to Garner’s aldehyde: Nozaki-Hiyama-Kishi coupling approach to sphingosines and ceramides

Abstract

The intermolecular Nozaki-Hiyama-Kishi coupling between alkenylchromium(III) reagents, derived from either (E)-2-bromostyrene or (E)-1-iodopentadec-1-ene, and conformationally rigid Garner's aldehyde resulted in stereoselective formation of Felkin-type allylic alcohols in good yields, thus providing an easy access to sphingosines. In addition, when the protecting group in Garner's aldehyde was changed (from Boc to N-octanoyl), a reversal of stereoselectivity was observed in the reaction with (E)-pentadec-1-enylchromium(III), probably as a result of hydrophobic interactions between long carbon chains of the reaction partners.