Heasley, Victor L.; Louie, Timothy J.; Luttrull, David K.; Millar, Mark D.; Moore, Hal B.; Nogales, Danny F.; Sauerbrey, Andreas M.; Shevel, Amy B.; Shibuya, Terry Y. published the artcile< Effect of N-bromosuccinimide (NBS) and other N-brominating agents on the bromination of α,β-unsaturated ketones in methanol>, HPLC of Formula: 112-63-0, the main research area is bromination unsaturated ketone ester regiochem; NBS bromine bromination unsaturated ketone regiochem; methoxybromoalkanone; alkanoate bromo methoxy.
Bromination of α,β-unsaturated ketones, e.g., RCH:CR1COR2 (I; R = R1 = H, R2 = Me, Ph; R = H, R1 = R2 = Me; R = R2 = Me, R1 = H) by Br in MeOH with and without NBS gave mixtures of Markovnikov bromides [e.g., RCHBrCR1(OMe)COR2], anti-Markovinkov bromides (e.g., MeOCHRCHBrCOR2), and dibromides (e.g., RCHBrCR1BrCOR2). The ratios of Markovnikov-anti-Markovnikov (M-AM) regioisomers were low without NBS and higher in the presence of NBS. The M-AM ratio for I (R = H, R1 = R2 = Me) was approx. the same with and without NBS. All of the ketones showed significantly less dibromide with NBS. The bromination rates decreased dramatically with NBS. Selected N-bromo amides (e.g., AcNHBr or AcNBr2) gave results similar to those of NBS with I (R = R1 = H, R2 = Me), showing small variations in the M-AM ratios. The ketones gave higher M-AM ratios with MeOBr-BF3. Bromination of esters (e.g., R3CH:CR4CO2Me; R3 = H, R4 = H, Me; R3 = Me, R4 = H), with and without NBS gave results parallel to those of the ketones, but with less change in the M-AM ratios. The mechanisms of the reactions are discussed. With the ketones, NBS functions by removing acid, causing a change from an acid-catalyzed mechanism to a bromonium ion-type mechanism, perhaps involving complexing between the olefin, NBS, and Br. The esters probably proceed by the latter mechanism in the presence of NBS.
Journal of Organic Chemistry published new progress about Bromination kinetics. 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, HPLC of Formula: 112-63-0.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics