Asymmetric construction of three contiguous stereogenic centers by conjugate addition-alkylation of lithium ester enolate.
A chiral ligand- and lithium amide-assisted asymmetric conjugate addition of lithium enolate of propionate to cyclopentenecarboxylate gave the corresponding lithium enolate, whose allylation gave the key intermediate of the marine alkaloid halichlorine as a single diastereomer with moderate enantioselectivity.
Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
Yasutomo
Y
Yamamoto
Yorinobu
Y
Yasuda
Hiroyuki
H
Nasu
Kiyoshi
K
Tomioka
D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D000478:Alkylation; D002384:Catalysis; D004952:Esters; D008094:Lithium / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000470:Alkaloids; D004952:Esters; D009942:Organometallic Compounds; D013141:Spiro Compounds; C412666:halichlorine; D008094:Lithium