“…13 C NMR (CDCl 3 ) of the 4d and the reduced products: δ 159.5, 158.9, 158. (26), 181 (9), 163 (7), 157 (5), 126 (10), 110 (7), 104 (10), 91 (9), 81 (6); m/z (relative intensity) of the reduced products: 154 (1), 153 (M + + 1, 11), 152 (M + , 100), 138 (5), 137 (71), 120 (3), 110 (5), 109 (82), 107 (10), 101 (9), 89 (8), 83 (44), 81 (7), 75 (8), 63 (12), 57 (13).…”