B 1605 (OTTO) p-Benzoquinone, 99% Cas 106-51-4 - used in the synthesis of bromadol and to suppress double- bond migration during olefin metathesis reactions. B 1605 (OTTO) p-Benzoquinone, 99% Cas 106-51-4 - used as a precursor to hydroquinone which finds application in photography and as a reducing agent and an antioxidant in rubber production.