In the screenshot attached taken from Khan Academy's video (https://www.youtube.com/watch?v=p9B4s0N5yk8&list=PL0pJUwkI0YCZRYrgKqHXZ0XCIu11afbJ8&index=3) the thick pink dot refers to a chiral carbon atom. Why is it that the two hydrogens circled red and pink that are bonded to a carbon which is then bonded to a chiral carbon atom are in different hydrogen environments? However, the three green circled hydrogens that are bonded to a carbon which are then bonded to a chiral carbon atom are in the same hydrogen environment?
From my understanding of hydrogen environment, a hydrogen environment is characterised by the functional group(s) that is attached to that hydrogen. Therefore, I think that the two hydrogens circled red and pink are in the same hydrogen environment, just like the three green circled hydrogens are in the same chemical environment.
Therefore, my question is why does a chiral carbon atom affect the hydrogen environment of a hydrogen? And especially from Khan Academy's example, only some hydrogens are affected by the chiral carbon and some aren't affected by it. Is there some loop hole in my understanding of hydrogen environment?