Selective Cleavage of β-Keto and Vinylogous β-Keto Esters by 3-Quinuclidinol

Investigation of the chemical changes during the thermal treatment of acrylonitrile‐co‐methyl acrylate‐polymer (polyacrylonitrile‐precursor) focusing on the fate of the methyl acrylate moiety

“…We propose that a Krapcho-analogous reaction with amines containing at least one N H bond instead of HCN acting as reagent will also (maybe even favored over the reaction pathway in Figure 34 with HCN) lead to the formation of carbon dioxide and the different detected methyl amines (Figure 35). This type of reaction is literature-known.. [37][38][39] The amount of about 10 mol% CO 2 relative to the MA content in combination with the found 1-2 mol% of trimethyl amine (not to count the also detected monand dimethyl amine) are in accordance with this mechanism and support that the main contribution is from the Krapcho-analogous reaction in Figure 35. Since the amount of formed carbon dioxide is smaller than the amount of still present methyl ester, the decarboxylation of structure motifs A and B from Figure 23 is a minor reaction under the applied conditions of thermal treatment.…”

Synthesis of tertiary phosphine derivatives of dihydrophenophosphazine

“…We have reported1 345"6 the carbalkoxylation of geminal diesters, ß-keto esters, and 5-keto-/3,7-unsaturated esters with the tertiary amine bases 1,5-diazabicyclo[4.3.0]non-5-ene (1), l,4-diazabicyclo[2.2.2]octane (2), and 3quinuclidinol (3), in nonaqueous solvents in good yields. The similarity of the bicyclic moiety of these bases with that found in alkaloids such as quinine and the fact that the substrates (ß-keto esters, geminal diesters, and 0keto-d,7-unsaturated esters) used are similar to those found in biological systems led us to postulate that one of the roles of alkaloids in plants could be to catalyze metabolic decarboxylation and decarbalkoxylation reactions.…”

“…After the mixture was heated to reflux for 2 h and cooled, the complex was decomposed by the slow addition of ice cold water (20 mL), followed by ice cold saturated aqueous NH4C1 (30 mL). Processing of the ether extract afforded the allylic alcohol 8: 3.3 g (quantitative); bt 60 °C (4 mmHg); NMR (CC14) 0.75 (3 H, t, J = 7 Hz, CH2CH3), 1.37 (2 H, m, CH2CH3), 2.0 (1 H, br, OH), 2.20, 2.80 (4 H, 2 m, 2CH2), 3.67, 3.73 (6 H, 2 s, 20CH3), 4.03 (1 H, t, J = 7 Hz, CHOH), 6.37 (2 H, br s, H, and H8), 6.53 (1 H, br s, H5), 6.70 (2 H, d, J = 9 Hz, H3/ and H8,), 6.93 (2 H, d, J = 9 Hz, H2, and Hg•); IR <w (neat) 3420 (OH); UV (ethanol) Xm" 224 (4.49), 314 (4.37). Anal.…”