# What is the reaction of epoxide with grignard reagent?

$R - M g X + {C}_{2} {H}_{4} O \rightarrow R - C {H}_{2} C {H}_{2} O M g X$
Clearly, the usual aqueous work-up will result in $R C {H}_{2} C {H}_{2} O H$, a primary alcohol that is 2 carbons longer than the original Grignard chain. Obviously this alcohol can be further elaborated to give for example an acid, an halide, or an olefin.