(a)(i) ene reaction, (ii) [2,3]-sigmatropic shift, (iii) [3,3]-sigmatropic shift
(b)(i) ene reaction, (ii) [3,3]-sigmatropic shift, (iii) [1,3]-sigmatropic shift
(c)(i) [2,3]-sigmatropic shift, (ii) ene reaction, (iii) [1,3]-sigmatropic shift
(d)(i) [1,3]-sigmatropic shift, (ii) [2,3]-sigmatropic shift, (iii) [3,3]-sigmatropic shift