A new class of chiral macrocyclic polythiacrown systems and a caveat1

Abstract

The reactions of 2,6-bis(bromomethyl)-cis-tetraoxadecalin (TOD) 3 with ethane-1,2-dithiol 4 (1,2-ethylenethioglycol, ETG) and the higher PETGs in Cs₂CO₃ promoted processes result in new polythiamacrocycles, having PETG bridges on or between cis-TOD crown systems in the ETG∶TOD ratios; 1∶1 (7), 2∶1 (17) and 3∶1 (18), as well as the unique 2∶2 (meso- and rac-8), 3∶3 (9) and 4∶4 (10) systems; 7 and 8 have been structurally (X-ray) analyzed. An important new observation and caveat: ETG undergoes a base (Cs₂CO₃, etc.) promoted oligo- and poly-merization process.