63791-85-5Relevant academic research and scientific papers
NOUVELLES METHODES DE DESHALOGENATION ET DE FORMATION D'ALKYLTRIMETHYLACETALS DE CETENE PAR ACTION DE iPr2NLi SUR QUELQUES α-BROMOESTERS
Lion, Claude,Lebbar, Kadija,Boukou-Poba, Jean-Paul
, p. 227 - 234 (2007/10/02)
A previously described method consisting in reacting LDA with α-bromoketones has been extended to α-bromoesters.Deshalogenation (after hydrolysis) and formation of ketene alkyltrimethylsilyl acetals (after SiMe3Cl addition) occur and show the generality of the method.
Deamination Reactions, 44. Decomposition of 1-Alkylcyclopropanediazonium Ions
Kirmse, Wolfgang,Rode, Jutta,Rode, Klaus
, p. 3672 - 3693 (2007/10/02)
1-Methyl- (17), 1,2-dimethyl- (41, 44), 1-propyl- (64), 1-(1-methylethyl)cyclopropanediazonium ions (80), and -1-diazonium ions (93) have been generated by alkaline cleavage of the analogous nitrosocarbamates in methanol.Cyclopropyl-allyl transformation and nucleophilic displacement were the only reactions of 17, 41, 44, and 93 while elimination and 1,2-shifts of an α-hydrogen compete increasingly with 64 and 80.The stereochemistry of ring cleavage and nucleophilic displacement has been explored, using 2-D labels in the case of 17 and 93.Cyclopropanediazonium ions (1) and 41 react stereospecifically, 17 and 44 are moderately stereoselective (ca. 85:15), and 93 is entirely unselective.The data indicate a gradual changeover from concerted to stepwise mechanisms.Appreciable stabilization of the positive charge is required to reach the SN1 extreme.
