4 5 6 7 9 9 July 8, 2019 16 32 64 128 9 5 6 x 7 4 9 4 5 (- 8y 7 )- 3 9 6 9y 4 ethyl 5 6 7 9 tetramethyldeca 2 9 diene 5 9z 6 9z 4 7 9z 9
