What are the differences between the Clemmensen reduction and the Wolff-Kishner reaction in terms of their mechanisms and applications in organic synthesis?

The Clemmensen reduction involves the use of zinc amalgam and hydrochloric acid to reduce carbonyl groups to alkanes, while the Wolff-Kishner reaction uses hydrazine and a strong base to achieve the same reduction. The Clemmensen reduction is more suitable for acid-sensitive compounds, while the Wolff-Kishner reaction is preferred for acid-stable compounds. Both reactions are commonly used in organic synthesis to convert carbonyl groups into alkanes.