Organic reduction of alkene

Can Wolff Kishner and Clemmensen Method be used to reduce alkyne or alkene. If so do they produce syn addition or anti addition product. ?




Zinc plus a proton source is known to reduce propiolates in THF [Tet. Letts. **46** 5613](https://www.sciencedirect.com/science/article/pii/S0040403905013973)


Rieke Zinc has been reported to reduce alkynes to \*cis-\*alkenes [Tet. Letts. **32** 299](https://www.sciencedirect.com/science/article/pii/S0040403900926121)
If you add catalytic Ni then Zn will reduce alkynes selectively to *cis* alkenes or *trans* alkenes depending on conditions [3](https://www.organic-chemistry.org/chemicals/reductions/zinc-zn.shtm) though this probably operates through Ni(O).


Zn/H+ does not reduce unactivated alkenes. Alkenes conjugated with an EWG may be reduced. 


W-K reduction relies on the hydrazine adding to a ketone to form a hydrazone in the 1st step. Nothing comparable can occur with an alkene. However hydrazine can reduce alkenes under different conditions by **Di-imide** reduction [review article](https://onlinelibrary.wiley.com/doi/abs/10.1002/0471264180.or040.02).


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