Glyoxal → 6-Ethoxy-3-methyl-3,6-dihydro-2H-pyran-2-carbaldehyde

반응식

[CH:1]([CH:3]=[O:4])=[O:2].O.C(C=O)=O.O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.[CH2:24]([O:26][CH:27]=[CH:28][CH:29]=[CH:30][CH3:31])[CH3:25].O1C=CC=CC1>>[CH3:31][CH:30]1[CH:29]=[CH:28][CH:27]([O:26][CH2:24][CH3:25])[O:2][CH:1]1[CH:3]=[O:4]

참가 물질

반응물 5

HCID 7860Glyoxal

HCID 14812Phosphorus oxide (P4O10)

HCID 186148Pyran

HCID 21880647Glyoxal hydrate

HCID 537696421-Ethoxy-1,3-pentadiene

생성물 1

HCID 205713736-Ethoxy-3-methyl-3,6-dihydro-2H-pyran-2-carbaldehyde

실험 절차

Monomeric glyoxal was generated by heating a mixture of 8.0 g. of glyoxal hydrate (0.117 mol. of monomer) and 48.0 g. of phosphorus pentoxide over a gentle flame over 35 minutes. The liberated monomer was bubbled (argon stream) into 4.8 g. (0.04 mol) of 1-ethoxy-1,3-pentadiene (purity 92.3%) at 120°. After all the monomer had been generated, the solution was heated at 120° for an additional 45 minutes. Distillation afforded 1.32 g. of the pyran (b0.07 =56°, purity 91%) and 1.86 g. of recovered diene (yield based on diene-32%, based on glyoxal=6.6%).