Synthesis of Sphingosine Relatives, XII Synthesis and Absolute Configuration of the Two Epimeric Aliphatic Amino Alcohols [5E, 7E)-2-Amino-5,7-tetradecadien-3-ols] Isolated from a Sponge,Xestospongia sp.

Abstract

(2S, 3S, 5E, 7E)- and (2S, 3R, 5E, 7E)-2-Amino-5,7-tetradecadien-3-ol [(S)-1a and (S)-1b], which were proposed as the structures of epimeric amino alcohols isolated from a marine sponge, and their two enantiomers were synthesized from (S)- and (R)-alanine, respectively. The high-field 1H-NMR spectra of the diacetyl derivatives of 1a, b were identical with those of the derivatives of naturally occurring amino alcohols. However, the absolute configurations of the natural products were corrected as (2R) by comparing the optical rotations of natural products with those of the synthetic products.