1) Create the ellipse, copy it and hide the copy;
2) Cut the ellipse at the top Anchor Point and Object>Path>Add Anchor Points some three or four times;
3) Create the first rectangle, Object>Transform>Move a copy to the right (horizontally);
4) Select both rectangles, Object>Blend>Blend Options set Orientation to Align to Path and set Spacing to Specified Steps and insert 11 (steps), then Object>Blend>Make;
5) Select both the blend and the ellipse and Object>Blend>Replace Spine.
6) Show the copy of the ellipse (from 1)), and bring it to the front if not already.
If you wish to have independent rectangles, you may then:
7) Object>Blend>Expand, and delete the redundant top rectangle.
The cut is to have a rectangle (set) at the top.
The adding of anchor points is to make an even distribution.
The 11 steps are because the last rectangle in the blend will be on top of the first one.