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imgur>com?4wBfp>jpg (change ? to / and > to . )
In the picture above, why does the second stereocenter have an S configuration and not an R? Based on priorities / atomic weights:
OH (left) = 1
CH2OH (bottom) = 2
CH3 (top) = 3
H (right) = 4
Since the lowest priority group, H, is horizontal, the configuration is the reverse of my answer: Original answer is S and then reversed it to R. But this answer is wrong... why?