In the study of chlorination of propane, four prouducts A, B, C, and D of the formula $C(3)H(6)C1(2)$ were isloated. Each of then was further chlorinated to provide trichloro products, $C(3)H(5)C1(3)$ . It was found that A provided one trichloro product, B gave two, and C and D each gave three. What the structural of A, B, C, and D ?
