Paraldol

Aldols can form dimers e.g. acetaldol 16 dimerizes to give paraldol 17 ... 

The first member of the group is acetaldoi (qv) which condenses on storage to paraldol... 

Some aldols serve for the prepn of explosives eg, paraldol, which on hydrogenation gives the 1,3-burylene glycol, yielding on nitration the explosive /, butylene-glycol dinitrate(qy)... 

Paraldehyde. See under Acetaldehyde A14-R Paraldol. See under Acetaldol A15-R Pentaerythritol Acetone.Compounds. See Acetone, Compounds of Pentaerythritol A40-L... 

On standing aldol changes to a viscous dimer from which paraldol [CH,CH(OH)CHjCHO]j separates. Wh tricllnic cryst, d 1.345 at 15.6/4°, nip 95—97° It boils in vacuo, under which condition part of it is reconverted to aldol. Sol in w or ale, si sol in eth. Unlike paraldehyde it shows some props of the aldehydes. Used as a raw material for making resins for plastics and syndi coatings(Ref 4). Acetaldol may be hydrogenated to form 1,3-buryIeneglycol from which the expl 1,3-butyleneglycol dinitrate may be prepd.(See also Aldol and Aldol Condensation)... 

A related phenomenon is the easy dimerization of some aldols upon standing an example is the conversion of aldol itself into paraldol (equation 13). Again, aldol can be regenerated by distillation of the dimer. 

---