An optically active compound a (assume that it is dextrorotatory) has the molecular formula c7h11br. a reacts with hydrogen bromide, in the absence of peroxides, to yield isomeric products, b and c, with the molecular formula c7h12br2. compound b is optically active; c is not. treating b with 1 mole of potassium tert-butoxide yields (+)-a. treating c with 1 mole of potassium tert-butoxide yields (±)-a. treating a with potassium tert-butoxide yields d (c7h10). subjecting 1 mole of d to ozonolysis followed by treatment with dimethyl sulfide yields two moles of formaldehyde and 1 mole of 1,3-cyclopentanedione (depicted). propose stereochemical formulas for a – d, and outline a reaction flow chart.