Alkene derivatives aluminum reagents

There are other organometallic derivatives that give Wittig-type olefination reactions, with titanium derivatives being the most commonly used. The initial addition reaction to the carbonyl gives a transient metal-ated alcohol that leads to an alkene. An example is the Tebbe reagent, which exists as a bridged methylene species (see 683), where Cp is cyclopentadienyl. 9 The aluminum species can be varied to include chloride... 

Lithium aluminum hydride is a very powerful reducing agent it reduces not only the carbonyl groups of aldehydes and ketones rapidly but also those of carboxylic acids (Section 17.6A) and their functional derivatives (Section 18.10). Sodium borohydride is a less reactive and therefore much more selective reagent, reducing only aldehydes and ketones rapidly. Neither reagent reduces alkenes or alkynes to alkanes. 

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