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