Synthesis of new macrocycles. Part I. Monomeric and dimeric o-phthalate esters
Abstract
Condensation of the dipotassium salt of o-phthalic acid with a series of alkyl dibromides of increasing chain length afforded cyclic esters ranging in size from a ten- to a thirty-four-membered ring. Dibromides bearing an uneven number of carbon atoms generally yielded dimeric compounds, while the even numbered dibromides gave monomeric compounds. The dimeric esters are highly crystalline and appear to exist in fixed conformations.