formaldehyde - Sciencemadness Dot Org

IMS FORMALDEHYDE
i-.n^ ;t!i a-i^-atiTrytic prnCf-T--,- :tnd there i> a growing- body of evidence that
!hi~ I- rhv fit-t 1 not only inv this reaction but also for orthodox aldol conu-ii-a-ior.^.
Larifrenbe'.-k" 3 report = that the aldol-type formaldehyde
f.mdcusatior: ir definitely catalyzed by glyccillic aldehyde, dihydroxyacetonc-
f'CH'iOH-CO-CH-iOH,, fructose. glucose, etc. The most active
catalyst.-? are giycollie aldehyde and dihydroxyaeetone, which are probably
the actual autoeatalysts. According to Langenbeck 35 , no induction period
L> observed when these agent? are added to alkaline formaldehyde.
The formation of giycollie acid and related compounds from formaldehyde
probably involves the formation of giycollie aldehyde as a primary
*xep. Hammicfc and Boeree- 3 obtained small yields of this acid by heating
paraformaldehyde with 10 per cent its. weight of concentrated sulfuric acid.
Fuchs and Katscher 24 obtained monochioroacetlc acid by heating trioxane,
;GH20>3t with suifuryl chloride and zinc chloride. Green and Handley- 7
claim the production of acetic acid by the action of heat and pressure on
formaldehyde.
Type Reactions
Most of the chemical reactions of formaldehyde with other compounds
may be broadly classified into three types: (a) reduction reactions, in which
the aldehyde acts a£ a reducing agent, itself being oxidized to formic acid;
ih) addition or condensation reactions, leading to the production of simple
methylol or methylene derivatives; and (c) polymerization reactions, resulting
in the formation of polymethylene derivatives.
Reduction Reactions. Formaldehyde is a reducing agent. In this
capacity it is most effective in alkaline solutions in which it is converted
to the formate ion. Latimer* 9 gives the potential (E°) for the half reaction
shown below as 1.14 international volts.
CEsO (aq) -f 3 OH"-*HC02" (aq) + 2HsO + 2