Convergent functional groups. 2. Structure and selectivity in olefin epoxidation with peracids

Abstract

at 90 MHz were satisfactory. In all cases p-dimethoxybenzene was the internal standard. The quartets at 1.942 and 2.317 due to the H4 protons were used for 7a and 8a respectively. Doublets at 1.150 and at 1.087 due to the 5-CH3 group were used for 7b and 8b respectively. Quartets at 2.330 and at 1.966 (H4 protons) and singlets at 2.188 and 2.100 (CH3CO-) were used for 10, 9,11, and 8c, respectively. The multiplet at 5.49-5.10 (H; and H3) and the triplet at 2.56 (H4 protons) were used for 7d and 8d, respectively.Rate of Reaction of CAN with Carbonyl Compounds. The rate of disappearance of CAN in solutions containing the various carbonyl compounds were determined by iodometric analysis in the absence and in the presence of 1,3-butadiene. With acetone, the half-life time of CAN was 5 h in the presence and 17 h in the absence of 1,3-butadiene. Corresponding values for 2-butanone were 0.75 and 2.3 h. With ethyl acetoacetate the disappearance of CAN was almost instantaneous in the presence of 1,3-butadiene, whereas in the absence of diene only 58% of CAN was reduced after 30 min. With 3-methyl-2-butanone reduction of CAN was complete after 8 and 24 h, in the presence and in the absence of 1,3-butadiene, respectively.Acknowledgment. Thanks are due to the Italian National Council of Research (CNR) and the Ministero della Pubblica Istruzione for financial support.Registry No. 7a, 100431-93-4; 7b (isomer 1), 100431-95-6; 7b (isomer 2),

Diastereoselective Epoxidation of Camphor N‐Enoylpyrazolidinones

“…Interestingly the reactivity was significantly enhanced when bulky b-substituted substrates were used (compare entries 3 and 4 with entries 1and 2). 10 This indicates that electrostatic properties play a critical role in the epoxidation process. The use of N-methacryloylpyrazolidinone (1f) gave moderate selectivity (entry 5).…”

Epoxidation of bacterial polyesters with unsaturated side chains. II. Rate of epoxidation and polymer properties

“…7 Similarly, an overall second-order reaction was found to apply to the epoxidation of PHOU up to fairly high reaction conversions, depending on the U unit content, according to the following equations:…”

“…Epoxidation reactions have been ap-plied to natural rubber and other unsaturated elastomers, 6 and many types of peracids, such as performic acid, peracetic acid, and m-chloroperbenzoic acid (MCPBA), have been used for these reactions and for the epoxidation of low molecular weight unsaturated compounds. [7][8][9] For polymers, it is particularly important that the reaction occur in a homogeneous phase without side reactions, especially chain scission and crosslinking.…”

Epoxidation of Polydienes Investigated by MALDI-TOF Mass Spectrometry and GPC-MALDI Coupling

“…The epoxidation of low molecular weight, unsaturated compounds in non-polar solvents, such as chloroform, generally gives excellent yields. [20] Using benzene, toluene, or xylene as solvent, the epoxidation of bacterial polyesters could be carried out without any side reaction. [21] Depending on the position of the double bond in a polymer chain the rate of epoxidation is quite different.…”