The synthesis of furans from acetylenic epoxides and diols
作者:D. Miller
DOI:10.1039/j39690000012
日期:——
Acetylenic αβ-epoxides react with dilute sulphuric acid and mercuric sulphate on heating to give furans in good yields; the reaction involves an internal hydration at a terminal acetylenic carbon atom. Under the influence of sulphuric acid alone, only small quantities of furans are formed; the major products are acetylenicdiols. These have been shown to be probable intermediates in the formation of
copper-catalyzed ring-opening reactions of racemic ethynyl epoxides with amines using (R)-DTBM-MeO-BIPHEP as a chiral ligand have been found to give the corresponding amino alcohols in high yields with up to 94% ee. The reaction is considered to proceed via copper−allenylidene complexes as key intermediates. This methodology may provide a novel synthetic approach to optically active amino alcohols, the structures