Expedient and Practical Synthesis of CERT-Dependent Ceramide Trafficking Inhibitor HPA-12 and Its Analogues
摘要:
The practical stereodivergent route to both syn- and anti-diastereomers of 1-substituted 3-aminobutane-1,4-diols based on the crystallization-induced asymmetric transformation (CIAT) approach was completed. This led to the revision of the reported stereochemistry of the first inhibitor of CERT-dependent ceramide trafficking HPA-12 from (R,R)-anti- to the (R,S)-syn-enantiomer. Due to the expeditiousness of production and inexpensive conditions developed, a series of alkyl- and aryl-substituted analogues of HPA-12 is also reported.
Acid-catalyzed lactonization in dilute hydrochloric acid of N-substituted 2-amino-4-aryl-4-hydroxybutanoic acids with electron donating aryl substituents is stereoconvergent. The stereochemical outcome is controlled by the precipitation of little soluble cis-lactones, starting from both syn-2-amino-4-aryl-4-hydroxybutanoic acids and anti-2-amino-4-aryl-4-hydroxybutanoic acids or their mixtures. A highly diastereoselective two-step sequence (acid-catalyzed lactonization with CIAT process followed by alkaline hydrolysis) for the transformation of syn-3b-d to the corresponding anti-3b-d is reported. (c) 2005 Elsevier Ltd. All rights reserved.