108811-41-2Relevant academic research and scientific papers
Anion structure determination in the gas phase: Chemical reactivity as a probe
Lee, Jeehiun K.,Grabowski, Joseph J.
, p. 9422 - 9429 (1996)
In the gas phase, the discrimination between two isomeric anion structures is a challenge that requires different solutions for different applications. The anionic oxy-Cope rearrangement involves the rearrangement of an alkoxide to an isomeric enolate; the mechanistic study of such a process in the gas phase requires a simple and selective probe process. Using a flowing afterglow mass spectrometer, we have examined the utility and limitations of using chemical reactivity to discriminate between alkoxides and enolates in the gas phase. A series of alkoxides and enolates were allowed to react with three chemical probe reagents: methanol-O-d, methyl nitrite, and dimethyl disulfide. Quantitative and qualitative characterization of each probe reagent reveals the especially broad and flexible utility of dimethyl disulfide as a chemical probe. Dimethyl disulfide is a selective reagent with ambident behavior that reacts efficiently with all anions studied and fully capitalizes on the structure/reactivity differences between alkoxides and enolates. Alkoxides behave as classical "hard bases" when allowed to react with dimethyl disulfide, effecting elimination across the C-S bond, whereas enolates, "soft bases", attack at sulfur. Methyl nitrite is also a selective ambident probe reagent but, due to its particularly slow reaction with enolates, is useful only in conjunction with a more reliable probe such as dimethyl disulfide. Methanol-O-d, for a variety of reasons detailed in the paper, is unsuitable as a chemical probe reagent for the unequivocal discernment between alkoxides and enolates.
Cyclization of (4-Methoxy-5-hexenyl)lithium
Bailey, William F.,Jiang, Xing-Long
, p. 6528 - 6533 (2007/10/02)
The cyclization of (4-methoxy-5-hexenyl)lithium (1), which was prepared by lithium-iodine exchange between 3-methoxy-6-iodo-1-hexene (2) and 1.75 molar equiv of t-BuLi in diethyl ether-n-pentane solution at -78 deg C, has been investigated in variety of solvent systems.The isomeric composition of the cis- and trans-1-methoxy-2-methylcyclopentane produced upon cyclization of 1 followed by quench with MeOH has been found to be dramatically dependent on the solvent system in which the isomerization is conducted.
