Preparation and Deprotection of Aldehyde Dimethylhydrazones
作者:Richard J. Petroski
DOI:10.1080/00397910600616776
日期:2006.7
Abstract Aldehydes were conveniently protected as dimethylhydrazones by stirring a mixture of the aldehyde, N,N‐dimethylhydrazine, anhydrous magnesium sulfate, and dichloromethane at room temperature. Azeotropic removal of water, formed during the course of the reaction, was not required because anhydrous magnesium sulfate functions as a water scavenger. Deprotection of aldehydedimethylhydrazones was accomplished
Two-Carbon Homologation of Aldehydes and Ketones to α,β-Unsaturated Aldehydes
作者:Richard J. Petroski、Karl Vermillion、Allard A. Cossé
DOI:10.3390/molecules16065062
日期:——
Phosphonate reagents were developed for the two-carbonhomologation of aldehydes or ketones to unbranched- or methyl-branched α,β-unsaturatedaldehydes. The phosphonate reagents, diethyl methylformyl-2-phosphonate dimethylhydrazone and diethyl ethylformyl-2-phosphonate dimethylhydrazone, contained a protected aldehyde group instead of the usual ester group. A homologation cycle entailed condensation of the
膦酸酯试剂被开发用于醛或酮的双碳同系化为未支化或甲基支化的 α,β-不饱和醛。膦酸酯试剂,二乙基甲基甲酰基-2-膦酸酯二甲基腙和二乙基乙基甲酰基-2-膦酸酯二甲基腙,含有受保护的醛基而不是通常的酯基。同系化循环需要将试剂与起始醛缩合,然后用 1 M HCl 和石油醚的双相混合物去除二甲基腙保护基团。这种稳健的两步法适用于各种醛和酮。在缩合和脱保护步骤后,不饱和醛产物的总分离产率为 71% 至 86%。