,, ... und ehrt mir ihre Kunst!“ – Evaluierung historischer und neuer Synthesewege zu 1,5-Dihydroxy-6-oxo-1,6-dihydropyridin-2-carbonsäure und 1,3-Dihydroxy-2-oxo-3-pyrrolin-4-carbonsäure / “. . . and honour their art!” – Evaluation of Historical and New Routes to 1,5-Dihydroxy-6-oxo-1,6- dihydropyridine-2-carboxylic Acid and 1,3-Dihydroxy-2-oxo-3-pyrroline-4-carboxylic Acid
摘要:
图形摘要
„... und ehrt mir ihre Kunst!“ – 评估历史和新的合成途径到1,5-二羟基-6-酮基-1,6-二氢吡啶-2-羧酸和1,3-二羟基-2-酮基-3-吡咯烯-4-羧酸 / “. . . and honour their art!” – 评估历史和新的合成途径到1,5-二羟基-6-酮基-1,6-二氢吡啶-2-羧酸和1,3-二羟基-2-酮基-3-吡咯烯-4-羧酸
Bis(1-cyanovinyl acetate) Is a Linear Precursor to 3-Oxidopyrylium Ions
作者:Sidney Malik Wilkerson-Hill、Shota Sawano、Richmond Sarpong
DOI:10.1021/acs.joc.6b02111
日期:2016.11.18
Herein we describe the first approach to 3-oxidopyrylium ions from a linear precursor. Heating bis(1-cyanovinyl acetate) in the presence of a trace amount of pyridinium p-toluenesulfonate results in a series of acyl group transfers and an intramolecular cyclization event to form a 3-oxidopyrylium ion that can be trapped by reaction with several dipolarophiles. When treated with dienes, the result is
The title compounds, 1,4-diacetoxy-1,4-dicyano-1,3-butadiene (3), 1,6-diacetoxy-1,6-dicyano-1,5-hexadiene (8), 1,2-bis(2-acetoxy-2-cyanovinyl)benzene (13), and 1,4-bis(2-acetoxy-2-cyanovinyl)benzene (17) were prepared by acetylation of the corresponding diacyl dicyanides. Dicyanides were prepared from diacyl chlorides by reaction with cyanotrimethylsilane or the NaI-Cu2(CN)2 reagent. Among the three geometrical isomers of the title compounds, the Z,Z diene predominated in 8 whereas E,E dienes predominated in conjugated dienes 3, 13, and 17. Conjugated E,E dienes underwent photoisomerization to E,Z and Z,Z isomers much faster than unconjugated diene 8. Prolonged irradiation on 13 yielded intramolecular [2 + 2] cycloadducts endo, exo- and exo,exo-5,6-diacetoxy-5,6-dicyano-2,3-benzobicyclo[2.1.1]hex-2-ene (22). Photochemistry in the formation of 22 is discussed.
Synthese von Acylcyaniden (α-Oxonitrilen) mit Cyanotrimethylsilan
作者:Klaus Herrmann、Gerhard Simchen
DOI:10.1055/s-1979-28619
日期:——
HERRMANN K.; SIMCHEN G., SYNTHESIS, 1979, NO 3, 204-205