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Arrow pushing or electron pushing is a technique used to describe the progression of organic chemistry reaction mechanisms. [1] It was first developed by Sir Robert Robinson . In using arrow pushing, "curved arrows" or "curly arrows" are drawn on the structural formulae of reactants in a chemical equation to show the reaction mechanism .
Hyperconjugation can be used to rationalize a variety of chemical phenomena, including the anomeric effect, the gauche effect, the rotational barrier of ethane, the beta-silicon effect, the vibrational frequency of exocyclic carbonyl groups, and the relative stability of substituted carbocations and substituted carbon centred radicals, and the thermodynamic Zaitsev's rule for alkene stability.
Arrow pushing for the Robinson annulation between 2-methylcyclohexan-1-one and but-3-en-2-one in the presence of sodium ethoxide as the base. The original procedure of the Robinson annulation begins with the nucleophilic attack of a ketone in a Michael reaction on a vinyl ketone to produce the intermediate Michael adduct. Subsequent aldol type ...
Hello, yes, the arrows are going in the wrong direction - Can think of the N-Li bond ionically like at the top of the article. The -ve charge on N attacks the H atom, so, equivalently, the N-Li bonding electrons would attack the H atom. The mechanism shown at present is a hydride abstraction, not a deprotonation.
Arrow pushing mechanism of DA INV.Bonds broken are labelled in red; bonds made are labelled in blue. The mechanism of the DA INV reaction is controversial. While it is accepted as a formal [4+2] cycloaddition, it is not well understood whether or not the reaction is truly concerted.
The prominent mechanism is a concerted pathway, meaning that it is a nonpolar, three-centered transition state with retention of stereochemistry. In addition, an S N 2 mechanism, which proceeds with inversion of stereochemistry, or a radical mechanism, which proceeds with obliteration of stereochemistry, are other possible pathways for ...
Arrow's theorem assumes as background that any non-degenerate social choice rule will satisfy: [15]. Unrestricted domain – the social choice function is a total function over the domain of all possible orderings of outcomes, not just a partial function.
Draw weights of adult compound bows range is between 40 and 80 pounds (18 and 36 kg), which can create arrow speeds of 250 to 370 feet per second (76 to 113 m/s). In the most common configuration, there is a cam or wheel at the end of each limb.