ABSTRACT
The generic term sphingosine is sometimes used to designate the naturally occurring long-chain sphingoid bases that are present in sphingolipids such as sphingomyelin, gangliosides, and cerebrosides. The first total chemical syntheses of sphingosine and sphingomyelin were reported by Shapiro et al. This classical method involves a Knoevenagel condensation of malonic acid with myristaldehyde, giving trans-2-hexadecenoic acid. The latter was converted into 3-O-benzoyl-dl-sphingosine in a lengthy procedure. Four different research groups developed the synthesis of sphingosine by the addition reaction of lithium pentadecyne to a protected, configurationally stable serine aldehyde. Carbohydrates have been important chiral starting materials for the preparation of sphingosine. One is removal of the "unnecessary" carbon units from the carbohydrate by oxidative cleavage of a glycol, generating an aldehyde that is used in Wittig olefination to give the long hydrocarbon chain of sphingosine. The other step is introduction of the amino group by activation of a sugar hydroxy group, followed by nucleophilic substitution with azide ion.
