1,2-Benzenedicarboxylic acid, mono(2-(2-(1-methylethoxy)-1-((1-methylethoxy)carbonyl)-2-oxoethylidene)-1,3-dithiolan-4-yl) ester 62052-64-6 Diisopropyl 4-hydroxy-1,3-dithiolan-2-ylidenemalonate phthalic acid semi-ester