Lithium borohydride (LiBH4) is a useful reducing agent, as

Chapter 13, Problem 13.69

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Lithium borohydride (LiBH4) is a useful reducing agent, as it is more selective than LAH but less selective than NaBH4. Unlike the latter, LiBH4 will reduce esters. However, it will not reduce amides (LAH reduces amides, as we will see in Chapter 21). This selectivity is frequently employed by synthetic organic chemists. For example, during a synthesis of (-)-croalbinecine, a natural product with cytotoxic properties, compound 1 was converted to compound 3, as shown below (J. Org. Chem. 2000, 65, 92499251). Draw the structures of 2 and 3. N O HO CO2Et 1) Excess NaH, excess PhCH2Br, DMF 2) H2O 1) Excess LiBH4 Ph 1 2 2) H2, Pd/BaSO4, quinoline, CH3OH 3 OCH3