Macrobislactone 1, 1, 4, 7-trioxa-cyclotridecane-8-13-dione, believed to be the cause of the fogging of car windscreens by an oily film, has been formally synthesised from diethylene glycol and adipic acid and its content in commercial polyester formulations has been estimated. Study of its ring-opening potential towards both anionic and enzymatic reagents reveal surprizing stability in polyester formulations, coupled with anomalous high ...