Allylicacetates were coupled with zinc dust in the presence of a catalytic amount of [Pd(PPh3)4] to give the corresponding 1,5-dienes under mild conditions in high yields. Significant co-solvent effects were found with methanol or 1,2-ethanediol in tetrahydrofuran.
Enantioselective Conversion of Oligoprenol Derivatives to Macrocycles in the Germacrene, Cembrene, and 18-Membered Cyclic Sesterterpene Series
作者:D. Srinivas Reddy、E. J. Corey
DOI:10.1021/jacs.8b10522
日期:2018.12.12
enantio-and diastereoselective process has been developed for the efficient conversion of farnesol and other oligoprenyl alcohols to chiral 10-, 14-, and 18-membered cyclization products, including germacrenol, (+)-costunolide, 3-β-elemol, and epi-mukulol. The key cyclization reaction utilizes ω-bromo aldehyde substrates, a chiral ligand, and indium powder as the reagent at -78 °C and generates 10-, 14-, and