Esters, from aldehydes

Diisobutylaluminium hydride reduces esters and ketones to alcohols at ordinary temperature. But at low temperature, it is used for the preparations of aldehydes from esters. 

Aldehydes from Esters and Nitriles RCO2R RCHO and RC=N RCHO... 

As with acid chlorides, other metal hydrides that permit isolation of the intermediate aldehydes have heen developed. For example, diisobutylaluminum hydride (DIBAL-H) reduces ketones to alcohols, but can be used to prepare the intermediate aldehydes from esters (Fig. 18.38). ... 

Hydrogenation in alcoholic acid converts ketones into ethers Good yields of aldehydes from esters as well as hydroxyaldehydes from lactones can be obtained by reduction with NaAlH4 at low temp. The preparation of aldehydes under mild conditions by cleavage of p-dimethylaminophenlycarbinols with diazotized sul-... 

Aldehydes may also be prepared from carboxylic acids via amide or ester intermediates. See section 51 (Aldehydes from Amides) and section 53 (Aldehydes from Esters)... 

This reaction is used in organic chemistry to separate an aldehyde from, for example, an ester. 

Silyl enol ethers are other ketone or aldehyde enolate equivalents and react with allyl carbonate to give allyl ketones or aldehydes 13,300. The transme-tallation of the 7r-allylpalladium methoxide, formed from allyl alkyl carbonate, with the silyl enol ether 464 forms the palladium enolate 465, which undergoes reductive elimination to afford the allyl ketone or aldehyde 466. For this reaction, neither fluoride anion nor a Lewis acid is necessary for the activation of silyl enol ethers. The reaction also proceed.s with metallic Pd supported on silica by a special method[301j. The ketene silyl acetal 467 derived from esters or lactones also reacts with allyl carbonates, affording allylated esters or lactones by using dppe as a ligand[302]... 

AkoJwIs may be obtained from aldehydes, ketones, esters, acid chlorides, and anhydrides,... 

Notable examples of general synthetic procedures in Volume 47 include the synthesis of aromatic aldehydes (from dichloro-methyl methyl ether), aliphatic aldehydes (from alkyl halides and trimethylamine oxide and by oxidation of alcohols using dimethyl sulfoxide, dicyclohexylcarbodiimide, and pyridinum trifluoro-acetate the latter method is particularly useful since the conditions are so mild), carbethoxycycloalkanones (from sodium hydride, diethyl carbonate, and the cycloalkanone), m-dialkylbenzenes (from the />-isomer by isomerization with hydrogen fluoride and boron trifluoride), and the deamination of amines (by conversion to the nitrosoamide and thermolysis to the ester). Other general methods are represented by the synthesis of 1 J-difluoroolefins (from sodium chlorodifluoroacetate, triphenyl phosphine, and an aldehyde or ketone), the nitration of aromatic rings (with ni-tronium tetrafluoroborate), the reductive methylation of aromatic nitro compounds (with formaldehyde and hydrogen), the synthesis of dialkyl ketones (from carboxylic acids and iron powder), and the preparation of 1-substituted cyclopropanols (from the condensation of a 1,3-dichloro-2-propanol derivative and ethyl-... 

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