Verfahren zur Herstellung von Ketenacetalen

摘要

The invention relates to a process for the preparation of ketene acetals by dehydrohalogenation of 2-haloaldehyde acetals, characterised in that the dehydrohalogenation is carried out a) for open-chain 2-haloaldehyde acetals, in the presence of an alkali metal or alkaline earth metal hydroxide and in the presence of a phase-transfer catalyst and/or a secondary or tertiary alcohol or secondary or tertiary diol, and b) in the case of cyclic 2-haloaldehyde acetals, in the presence of an alkali or alkaline earth metal hydroxide and in the presence of a phase-transfer catalyst and optionally a secondary or tertiary alcohol or secondary or tertiary diol, or in the presence of an alkali or alkaline earth metal hydroxide and a secondary or tertiary diol. The ketene acetals which can be prepared by means of the process according to the invention are used as intermediates in organic synthesis and are suitable as monomers or comonomers for free-radical polymerisation for the preparation of biodegradable plastics.