What is Corey-House alkane synthesis

Corey –House synthesis involves the formation of alkanes through following steps:

1) Reaction of alkyl halide with lithium, in dry ether to form alkyl lithium:

2) Reaction of alkyl lithium with CuI to form dialkyllithiumcuparate known as Gilman reagent.

3) Reaction of dialkyllithiumcuparate with alkyl halide to give alkane:

This method is mainly used to prepare alkanes of R-R’ type.