Aldimines are conveniently metallated, at a position α to the functional group, by using very powerful bases i.e. activated lithium dialkylamides generated in situ from lithium and a secondary amine in benzene/hexamethylphosphoric triamide. The anions obtained are alkylated with various ω,ω′-dihalogenoalkanes to give, after aqueous acid hydrolysis, good yields of ω-halogenated aldehydes and dialdehydes
Identification and analysis of persistent contaminants associated with gemcadiol
作者:J. Philip、D.H. Szulczewski
DOI:10.1002/jps.2600690620
日期:1980.6
of the investigational new drug gemcadiol (2,2,9,9-tetramethyl-1,10-decanediol) were contaminated with impurities whose nature and source were unknown. Subsequent study showed that these impurities consisted of polymeric material formed by self-condensation of the dialdehyde precursor. Gel permeation chromatographic techniques were found to be useful in the analysis of polymers present in both the