| abstract |
"Process for the preparation of glyoxal monoacetals" ABSTRACT OF THE DISCLOSURE This process for the preparation of products of general formula (I): (I) wherein either R1 and R2, which are identical, represent a -CHRR3 group, in which R and R3, which are identical or different, represent an alkyl, alkenyl or aralkyl group, or R1 and R2, which are identical, represent a -CH2R group, in which R represents a hydrogen atom, an alkyl, alkenyl or aralkyl radical, or R1 and R2 together form a -CH2-(CRR)n-CHR-radical, in which n represents 0 or 1 and R retains the meaning given previously, is characterised by reacting glyoxal in the presence of an acid catalyst with an excess of the corresponding alcohol of general formula (II) RR3CHOH, (III) RCH2OH or (IV) HOCH2-(CRR)n-CHROH, in which R, R3 and n retain the meaning given previously, then stopping the reaction as soon as the concentration of the desired monoacetal of general formula (I) decreases in the reaction medium in favour of bisacetal. Application to the preparation of the novel product: 2,2-diallyloxy ethanal. |