Orgo numbering question

[Mrhyde]

I dont understand the way this picture is numbered ???? Where they put the red number one there is no carbon, so how can that oxygen be carbon one?

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[Samin23]

The molecule is numbered for chirality purposes. In this case, the 1* Oxygen has the highest priority (since it is bonded to a carbon on the other side), and the other oxygen is 2* (because it is bonded to a hydrogen, which is smaller than a carbon when comparing to 1*). The red 3* priority goes to the carbon in the bottom right of the cyclic ring because carbon has a smaller atomic number than oxygen. The 4* priority goes to hydrogen, which is not drawn. The blue numbers refer to a different chiral center.