[yuriljx]

                                                    NaNH2
1. CH3-CH2-CH2-CH2-CΞC-CH3-------->
                                                 OsO4
2.CH3-CH2-CH=CH-CH2-CH3----------->                   (only OsO4, draw both enantiomers)
                                                                  LiAlD4
3 CH3-CH2-CH2-CHBr-CH2-CH2-CH2-F--------->       

it's gonna be much better if the answer can show the stereochemistry when relevant
               

[cpncoop]

I have the feeling you haven't tried these problems yourself yet.  The second one, for sure, is very clearly described in any organic chemistry book.  If you try the problem, and still cannot solve it, please let me know.... but at least try it first.