Sphingosines glycosylation with

After glycosylation with sphingosine the azide group is reduced to an amine. Hydrogen sulfide in pyridine / water hereby acts as reducing reagent. Next stearic acid (75) has to be connected to the amine - a peptide bond is formed. 

Two pathways are known for the formation of cerebrosides from sphingosine. The quantitative significance of the two synthetic mechanisms is unresolved. In the first pathway, sphingosine is glycosylated with a UDP-sugar (UDP-galactose usually studied) to yield psychosine. The latter is then acylated with an acyl-CoA (Fig. 11.21). Alternatively, the acylation occurs before the glycosylation (Fig. 11.21). 

Glycosylation of Trichloroacetimidates of D-Galactose with Sphingosine Derivative 6B... 

---