Copper-catalysed enantioselective intramolecular etherification of propargylic esters: synthetic approach to chiral isochromans.

Enantioselective synthesis of chiral isochromans bearing a terminal alkyne moiety has been accomplished by copper-catalysed enantioselective intramolecular propargylic substitution reactions of propargylic esters with alcoholic nucleophiles. This method represents the first successful example which directly introduced a terminal alkyne group into chiral isochromans.