(1) Two derivatives of aluminium hydride that are less reactive than LiAlH₄ are Lithium tri-tert-butoxyaluminium hydride and Diisobutylaluminium hydride (DIBAL-H) because these are much more sterically hindered and therefore have difficulty in transferring hydride ions. These reagents are used to convert acid derivatives like acid chloride, ester, nitrile etc. into aldehyde.