Some of the most useful compounds for organic synthesis are Grignard reagents (general formula R±MgX, where X is a halogen), which are made by combining an alkyl halide, R±X, with Mg. They are used to change the carbon skeleton of a starting carbonyl compound in a reaction similar to that with R - Li:(d) What carbonyl compound must react with a Grignard reagent to yield a product with the - OH group at the end of the carbon chain?