Haloaldehyde polymers. 63. Diacyl-terminated trihaloacetaldehyde oligomers

Mixtures of diacyl-terminated trichloroacetaldehyde (chloral) oligomers wer e synthesized using tertiary amines as initiators followed by end-capping w ith diacyl anhydrides. Not only were the oligomeric alkoxide molecules acyl end-capped when the reaction mixture was treated with the acid anhydride, but the initiator fragment that was attached to the initiated end was also replaced by an acylate group. Eight different anhydrides were used for end- capping reactions allowing us to synthesize a number of symmetric chloral o ligomers diacylates. A mechanism for the oligomerization of the chloral mon omer was proposed on the basis of the results obtained from these investiga tions. Similar oligomerizations of bromal initiated with tertiary amines, a nd end-capped with acetic anhydride, gave the corresponding oligomeric brom al diacetates. All the trihaloacetaldehyde oligomer mixtures were analyzed by gas chromatography and the individual components were identified by K+ID S mass spectrometry.