Question

how to draw newman projection for different structure

Answer 1

A Newman projection, useful in alkane stereochemistry, visualizes chemical conformations of a carbon-carbon chemical bond from front to back, with the front carbon represented by a dot and the back carbon as a circle (see below). The front carbon atom is called proximal, while the back atom is called distal. This type of representation is useful for assessing the torsional angle between bonds

Answer 2

Thanks
and one more thing i know r, s configuration but cannot draw in a chair conformation