Reaction of tetracyanoethylated ketones with aldehydes. Synthesis of 3-imino-2,6-dioxabicyclo[2.2.2]octanes

A novel method for the domino synthesis of 6-imino-2,7-dioxabicyclo[3.2.1]octane-4,4,5-tricarbonitriles and studies of stereochemical characteristics of formation and structure thereof

“…Not only does the system used accelerate the reaction, but also makes it possible even for those species of aliphatic tetracyanoethylated ketones 1 which do not form products with aldehydes 2k,l,p under the conditions of the known method. 6 The structure of obtained compounds is confirmed by IR and 1 H NMR spectroscopy, mass spectrometry, and elemental analysis data. In addition, 13 C NMR spectra were recorded for compounds 2d,m,n.…”

“…One approach to this objective is the selection for use in directional synthesis of special functionally prearranged substrates, which include, in particular, 4-oxoalkane-1,1,2,2-tetracarbonitriles 1. [1][2][3][4][5][6] It was reported earlier 6 that substituted 3-imino-2,6-dioxabicyclo[2.2.2]octane-4,8,8-tricarbonitriles 2' form as products of the reaction of tetracyanoethyl ketones 1 with aldehydes (Scheme 1). However, the structure was later elucidated by single crystal X-ray structural analysis and it was found that 6-imino-2,7-dioxabicyclo[3.2.1]octane-4,4,5-tricarbonitriles 2 form as a result of this reaction.…”

“…With the aim of studying the stereochemical characteristics of this reaction in more detail, as well as obtaining new derivatives 2, we have developed a modified method of synthesizing previously unknown 1-and 8-arylsubstituted dioxabicycles 2, whose synthesis by the known method 6 proved impossible. Furthermore, the starting Scheme 1 reagents were selected so that upon further study of the biological activity its correlation with the structure of the compound could be established, in particular, the degree of influence of the aryl substituent at a specific position R 1 or R 2 in the presence of an alkyl substituent R 3 could be examined, as well as the expected synergistic effect with substituent R 3 also being aromatic could be investigated.…”