new index atom name original index 1 C 14 2 C 13 3 C 11 4 C 12 5 C 10 6 C 9 7 C 5 8 C 8 9 C 7 10 C 4 11 C 6 12 O 3 13 O 2 14 O 1 15 H 20 16 H 22 17 H 21 18 H 19 19 H 17 20 H 18 21 H 16 22 H 15