Name the following compounds by assigning the absolute configuration (R) or (S)

Solution

The main chain with the longest length (4 carbons) is chosen. The numbering gives the lowest locant to the functional group (-OH). In position 2 there is a chiral center with notation R.





The molecule is drawn in a Fischer projection. To name it, the chain with the longest length is chosen as the main one and it is numbered so that the hydroxyl groups take the least locants. Carbon 2 is chiral, and it is necessary to indicate its notation (R or S) in the name. As in previous examples, we prioritize chains starting from carbon 2 by atomic number. We look at the position of the group "d", if it is above or below in the projection, the rotation in the direction of the needles gives the notation R and in the opposite direction S. When the group "d" is to the right or left in the projection, turning clockwise gives notation S and in the opposite direction R.