(S-(R*,R*))-2,3-Dihydroxybutanedioic acid, bis(1-methylethyl) ester 62961-64-2 Butanedioic acid, 2,3-dihydroxy-, bis(1-methylethyl) ester, (S-(R*,R*))- Diisopropyl (S-(R*,R*))-tartrate EINECS 263-771-4