Question

Draw (S,E)-1-(methylamino)but-2-en-1-ol.

Be sure to add all bonds at stereocenters (including to hydrogens).

Answer 1

deciding E-Z:
If the two groups with the higher priorities are on the same side of the double bond, that is described as the (Z)- isomer.

If the two groups with the higher priorities are on opposite sides of the double bond, then this is the (E)- isomer

deciding R and S:
Give priority to all the 4 bond attached to chiral centre.

To decide R or S
If 4th priority bond is into the plane and 1-2-3 rotate clockwise ---> R
If 4th priority bond is into the plane and 1-2-3 rotate counter clockwise ---> S

If 4th priority bond is Not into the plane and 1-2-3 rotate clockwise ---> S
If 4th priority bond is Not into the plane and 1-2-3 rotate counter clockwise ---> R