Die Synthese von 4‐substituierten Bicyclo[2.2.2]oct‐1‐yl‐p‐nitrobenzolsulfonaten

Abstract

Synthesis of 4-Substituted Bicyclo[2.2.2]oct-1-yl-p-Nitrobenzenesulfonates SummaryThe syntheses of the 4-substituted bicyclo [2.2.2]oct-1 -yl-p-nitrobenzenesulfonates 1 a-2s are described.Fur eine Untersuchung, uber welche gesondert berichtet wird [I], wurden die 4-R-substituierten Bicyclo [2.2.2]oct-1 -yl-p-nitrobenzolsulfonate (Nisylate) 1 a-1 s benotigt. Im folgenden wird ihre Synthese beschrieben.Zur Synthese der meisten dieser Nisylate schien der bekannte 4-Hydroxybicyclo [2.2.2]octan-1 -carbonsaureathylester (7) ein geeignetes Zwischenprodukt zu sein, doch befriedigten die bisherigen, umstandlichen Herstellungsverfahren [2] [3] nicht, da sie relativ geringe Gesamtausbeuten (1-2%) ergeben. Besser verlauft das folgende siebenstufige Verfahren.Der bekannte [4], aber unvollstandig beschriebene Triester 2 entstand durch Michael-Addition von zwei Mol-Aquiv. Acrylsaureathylester an Acetessigsaureathylester in Gegenwart von Benzyltrimethylammonium-hydroxid in 93% Ausbeute. Partielle Verseifung der primaren Estergruppen mit NaOH lieferte in

Through-bond transmission of substituent effects in the bicyclo[2.2.2]octane ring system: solvolysis of 4-deuterio- and 4-metalloidal (M(CH3)3, M = silicon, germanium and tin)-substituted bicyclo[2.2.2]oct-1-yl p-nitrobenzenesulfonates and methanesulfonates

“…The reaction mixture was then refluxed for 1 h before being allowed to stir overnight at ambient temperature. Following workup as prescribed by Strating et al,42 the crude silyl ether was distilled (75 °C/0.2 mm) to afford a white solid (12.05 g, 99%): mp 42-44 °C; NMR (CDC13) b 0.00 (9, s, SiMe3), 1.50-2.48 (12 H, m, CH2CH2); 13C NMR (CDC13) b 61.66 (Cl), 38.86 (C2), 37.00 (C3), 69.24 (C4), 2.63 (OSiMe3). 4-Deuteriobicyclo(2.2.2]octan-l-ol (1: X = D, Y = OH).…”

Design and Synthesis of Novel 19F-Amino Acid: A Promising 19F NMR Label for Peptide Studies

“…Double alkylation of 8 with BrCH 2 CH 2 Cl using LDA/HMPA afforded the bicyclic derivative 9 in 72% yield following the literature procedure. , Monohydrolysis of the ester group in 9 using 1 equiv of NaOH in methanol/water mixture gave acid 10 in 55% yield . Finally, the crucial step, conversion of the carboxylic group in 10 into the fluorine atom with XeF 2 , was attempted. The reaction in CH 2 Cl 2 afforded a mixture of the target fluoride 4 and the side product 11 , however .…”

A Molecular Torsion Balance Study: A Nearby Anionic Group Exerts Little Influence on Hydrophobic Interactions between Nonpolar Surfaces

“…The synthesis of the bicyclo[2.2.2]octyl alcohol series 12 (Scheme ) followed Grob and Rich's method . It began with the reaction of diethyl acetoacetate and ethyl acrylate.…”

“…The synthesis of the bicyclo[2.2.2]octyl alcohols eries 12 (Scheme 2) followed Grob and Rich's method. [18] It began with the reaction of diethyla cetoacetatea nd ethyl acrylate. The resulting triester 14 was hydrolyzedt og enerate diacid 15,w hich then afforded keto-ester 16 throughd ecarboxylative cyclization.…”