1273005-76-7Relevant academic research and scientific papers
Formal total synthesis of (+)-lysergic acid via zinc(II)-mediated regioselective ring-opening reduction of 2-alkynyl-3-indolyloxirane
Iwata, Akira,Inuki, Shinsuke,Oishi, Shinya,Fujii, Nobutaka,Ohno, Hiroaki
experimental part, p. 5506 - 5512 (2011/08/22)
Asymmetric formal synthesis of (+)-lysergic acid was achieved with a reductive ring-opening reaction of chiral 2-alkynyl-3-indolyloxirane with NaBH3CN as the key step. With Zn(OTf)2 as an additive, the ring-opening reaction proceeded regioselectively at the 3-position to give the corresponding propargyl alcohol, which was a precursor of the allenic amide for palladium-catalyzed domino cyclization to construct the ergot alkaloid core structure.
Enantioselective total synthesis of (+)-lysergic acid, (+)-lysergol, and (+)-isolysergol by palladium-catalyzed domino cyclization of allenes bearing amino and bromoindolyl groups
Inuki, Shinsuke,Iwata, Akira,Oishi, Shinya,Fujii, Nobutaka,Ohno, Hiroaki
experimental part, p. 2072 - 2083 (2011/05/12)
Enantioselective total synthesis of the biologically important indole alkaloids (+)-lysergol, (+)-isolysergol, and (+)-lysergic acid is described. Key features of these total synthesis include (1) a facile synthesis of a chiral 1,3-amino alcohol via the Pd(0)- and In(I)-mediated reductive coupling reaction between l-serine-derived 2-ethynylaziridine and formaldehyde; (2) the Cr(II)/Ni(0)-mediated Nozaki-Hiyama-Kishi (NHK) reaction of an indole-3-acetaldehyde with iodoalkyne; and (3) Pd(0)-catalyzed domino cyclization of an allene bearing amino and bromoindolyl groups. This domino cyclization enabled direct construction of the C/D ring system of the ergot alkaloids skeleton, as well as the creation of the C5 stereogenic center with transfer of the allenic axial chirality to the central chirality.
