Z-selective intramolecular Horner-Wadsworth-Emmons reaction for the synthesis of macrocyclic lactones.
When the substrates (ArO)(2)P(O)CH(2)CO(2)---CHO (Ar = Ph, o-t-BuPh) were added to a THF solution containing 3 equiv of NaH at 0 degrees C or NaI-DBU at rt over 1-10 h, the intramolecular Horner-Wadsworth-Emmons reaction proceeded efficiently to give the 12-18-membered-ring lactones in 69-93% yields with 89-100% Z selectivity. On the other hand, (EtO)(2)P(O)CH(2)CO(2)---CHO gave the 13-18-membered-ring lactones in 52-82% yields with 89-99% E selectivity using LiCl-DBU in MeCN or THF.
Ando
Kaori
K
Department of Chemistry, Fuculty of Engineering, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan. ando@gifu-u.ac.jp
Narumiya
Kenji
K
Takada
Hirokazu
H
Teruya
Taiji
T
D003500:Cyclization; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D047028:Macrocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
D007783:Lactones; D047028:Macrocyclic Compounds