Hydrolysis;

1: dipyridinium dichromate; acetic acid / ethyl acetate / 16 h / 20 °C 2: caesium carbonate / tetrahydrofuran / 0.5 h / 0 °C / Inert atmosphere 3: Oxonereg;; C8H6O4(2-)*Cu(2+) / toluene / 6 h / 60 °C / Molecular sieve; Air atmosphere 4: N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile / tetrachloromethane 5: toluene-4-sulfonic acid / toluene / 1 h / Reflux View Scheme

1: dipyridinium dichromate; acetic acid / ethyl acetate / 16 h / 20 °C 2: Oxonereg;; C8H6O4(2-)*Cu(2+) / toluene / 7 h / 60 °C / Molecular sieve; Air atmosphere 3: N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile / tetrachloromethane / Reflux View Scheme