102THE CANNIZZARO REACTIONof the lime required in the above equation generally is used,48'49>60although less than the stoichiometric amount of the base has beenrecommended in at least one instance.61The use of promoters such ascopper oxalate,62formamide,62and sugarsMhas been described, as hasalso the use of quaternary ammonium bases.44The preparation of pentaerythritol in 56% yield on a laboratory scalehas been described inOrganic Syntheses.*6'iSThe modified procedureof Friederich and Brunn47gives better yields and is described in theexperimental part (p. 111).Propionaldehyde65and isovaleraldehyde66have been converted tothe corresponding trimethylol derivatives, CH3C(OH2OH)3and(CH3)2CHC(CH2OH)3, by treatment with formalin and calcium hydrox-ide;although the yields are not specified they appear to be good. Phen-ylacetaldehyde66did not give the expected product.The only useful Cannizzaro reactions involving the use of aldehydes
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