Malondialdehyde aus Propinai / Malonaldehydes from Propynal

Abstract

Malonaldehyde (2 a) is possibly an intermediate in the reaction of propynal (1) with itself, which ends up in 3-ethinyl-2,4-diformyl-pentanedial (6 a), a compound containing two malonaldehyde groups bridged by a substituted methylene group. The alkali salts of the unstable 1-thiomalonaldehyde (7 a) are obtained from 3,3′-thiodiacroleine (8 a) or S-acroleinyl-diphenylthiourea (8 b) and alkalisulfide or ammonia. 2-Chloro, 2-bromo- and 2-iodo-malonaldehyde (14 a-c) are prepared from 1 via 2,3-dihalogenpropenals (12).