requires three chemical steps, i.e. reduction, oxidation and olefination (Figure 1) [9,10]. When the benzyl group is used as protecting group for the nitrogen functionality, the method represents a variation of the well-known Reetz protocol [11]. In the particular case of serine and threonine, additional O-protection and O-deprotec- tion steps are required (Figure 1). Thus, Garner’s aldehyde [12,13] or N- and O-protected amino ester derivatives have been required