Pinacol cross coupling of 2-[N-(alkoxycarbonyl)amino] aldehydes and aliphatic aldehydes by [V2Cl3(THF)6]2[Zn2Cl 6]. Synthesis of syn,syn-3-[N-(alkoxycarbonyl)amino] 1,2-diols

Article abstract of DOI:10.1021/ja00083a017

Slow addition of 2-[N-(alkoxycarbonyl)amino] aldehydes to mixtures of [V₂Cl₃(THF)₆]₂[Zn₂Cl ₆] and aliphatic aldehydes gave syn,syn-3-[N-(alkoxycarbonyl)amino] 1,2-diols in good yield and high enantiomeric purity (>99:1). The alkyl group of the N-alkoxycarbonyl was shown to influence the yield: Me > allyl > Bn > t-Bu. Only the syn,syn diastereomer was observed (>20:1), except with N-Cbz-alaninal (10:1:1), O-benzyl-N-Cbz-serinal (7:1), and N-Cbz-prolinal (5:1 to 12:1). A new serinai derivative, N-Cbz-O-TBS-serinal, was cross coupled with n-pentadecanal to give a derivative of xylo-D-C₁₈-phytosphingosine.