The hydrodimerization of acrolein by electro-reduction was written by Misono, Akira;Osa, Tetsuo;Yamagishi, Takamichi. And the article was included in Nippon Kagaku Zasshi in 1966.Product Details of 13417-49-7 This article mentions the following:
Electrolytic reduction of CH2:CHCHO (I) was carried out in Et4N+.p-MeC6H4SO3– (II), Bu4N +Br– (III), or p-MeC6H4SO3H (IV) solution with Hg cathode. The monomeric products were EtCHO, CH2 :CHCH2OH, and PrOH, the yield being low. In aqueous II, 1-formylcyclopentene (V) and 1-cyclopentenylcarbinol (VI) were formed, whose formation can be explained by considering OHC(CH2)4CHO (VII) formed by β-dimerization of I. In aqueous IV, 3-formyl5,6-dihydro-2H-pyran (VIII) was obtained in addition to V and VI. Some polymers and Hg compound were also obtained. In aqueous II, current efficiency (ηv) for formation of V increased with increasing concentration of II, had a maximum at ∼15 g./120 ml. concentration of I and had a maximum at -1.2 v. cathode potential when the potential was changed. On the other hand, current efficiency (ηpr) for formation of PrOH had a min. at ∼20 g./120 ml. concentration of I. Addition of p-(HO)2C6H4 (IX) did not affect the current efficiency. In aqueous IV, both ηv and ηpr increased with increasing concentration of IV but the effect was strongest for current efficiency for formation of VIII. ηv increased with increasing c.d. and decreased when IX was added. Electrolysis of I in the presence of CH2:CHCO2Et did not give any codimerization product. Polarography of I in aqueous III showed E1/2-1.37 v. which corresponded to reduction of C:C. Addition of IV shifted the half wave potential to -1.30 v. Headhead dimerization is postulated to proceed via addition of monomer anion in nucleophilic fashion to form VII which condenses to on heating. Formation of VIII is attributed to hydration of I followed by addition to form O(CH2CH2CHO)2. In the experiment, the researchers used many compounds, for example, 5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7Product Details of 13417-49-7).
5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7) belongs to tetrahydropyran derivatives. In organic synthesis, the 2-tetrahydropyranyl group is used as a protecting group for alcohols. Pyran derivatives such as pyran flavonoids are biologically important. Monosaccharides containing six-membered rings are called pyranose.Product Details of 13417-49-7
Referemce:
Tetrahydropyran – Wikipedia,
Tetrahydropyran – an overview | ScienceDirect Topics