Sanjoinine-G1 (1), a 14-membered cyclopeptide, was synthesized with st
ereoselective reactions. Started from D-serine, a cyclic precursor for
various frangulanine type 14-membered cyclopeptide alkaloids was synt
hesized and the side chain acylation product was identical with the na
tural sanjoinine-G1 (17 steps, overall yield 1.36%).