SAYTZEFF RULE PDF

Alkyl groups are electron donating by inductive effect, and increase the electron density on the sigma bond of the alkene. Also, alkyl groups are sterically large, and are most stable when they are far away from each other. In an alkane, the maximum separation is that of the tetrahedral bond angle, As a result, the separation between alkyl groups is greatest in the most substituted alkene. In regards to orbital hybridization , a bond between an sp2 carbon and an sp3 carbon is stronger than a bond between two sp3-hybridized carbons. The removal of the proton and the loss of the leaving group occur in a single, concerted step to form a new double bond.

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Alkyl groups are electron donating by inductive effect, and increase the electron density on the sigma bond of the alkene. Also, alkyl groups are sterically large, and are most stable when they are far away from each other. In an alkane, the maximum separation is that of the tetrahedral bond angle, As a result, the separation between alkyl groups is greatest in the most substituted alkene.

In regards to orbital hybridization , a bond between an sp2 carbon and an sp3 carbon is stronger than a bond between two sp3-hybridized carbons. The removal of the proton and the loss of the leaving group occur in a single, concerted step to form a new double bond. When a small, unhindered base — such as sodium hydroxide , sodium methoxide , or sodium ethoxide — is used for an E2 elimination, the Zaitsev product is typically favored over the least substituted alkene, known as the Hofmann Product.

For example, treating 2-bromomethylbutane with sodium ethoxide in ethanol produces the Zaitsev product with moderate selectivity. In these situations, a less sterically hindered proton is preferentially abstracted instead. As a result, the Hofmann Product is typically favored when using bulky bases.

When 2-bromomethylbutane is treated with potassium t-butoxide instead of sodium ethoxide, the Hofmann product is favored. These intramolecular interactions are relevant to the distribution of products in the Hofmann elimination reaction, which converts amines to alkenes.

In the Hofmann elimination, treatment of a quaternary ammonium iodide salt with silver oxide produces hydroxide ion, which acts as a base and eliminates the tertiary amine to give an alkene. The quaternary ammonium group is large, and interactions with alkyl groups on the rest of the molecule are undesirable. As a result, the conformation necessary for the formation of the Zaitsev product is less energetically favorable than the conformation required for the formation of the Hofmann product.

As a result, the Hofmann product is formed preferentially. The Cope elimination is very similar to the Hofmann elimination in principle, but occurs under milder conditions.

It also favors the formation of the Hofmann product, and for the same reasons. For example, when menthyl chloride is treated with sodium ethoxide, the Hofmann product is formed exclusively: [13] but in very low yield: [14] This result is due to the stereochemistry of the starting material.

E2 eliminations require anti-periplanar geometry, in which the proton and leaving group lie on opposite sides of the C-C bond, but in the same plane. When menthyl chloride is drawn in the chair conformation , it is easy to explain the unusual product distribution. Formation of the Zaitsev product requires elimination at the 2-position, but the isopropyl group — not the proton — is anti-periplanar to the chloride leaving group; this makes elimination at the 2-position impossible.

In order for the Hofmann product to form, elimination must occur at the 6-position. Because the proton at this position has the correct orientation relative to the leaving group, elimination can and does occur. As a result, this particular reaction produces only the Hofmann product.

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SAYTZEFF RULE PDF

Mizilkree The bulkiness of the base also increases the Hoffmann product at the cost of the Zaitsav product. Because the proton at this position has the correct orientation relative to the leaving group, elimination can and does occur. These intramolecular interactions are relevant to the distribution of products in the Hofmann elimination reaction, which converts amines to alkenes. As a result, this particular reaction produces only the Hofmann product. Saytzeff Rule and Elimination Major Product Perhaps one of the main reasons Zaitsev began investigating elimination reactions was to disprove his rival. For butene, it has 2 alkyl groups attached to the alkene.

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Zaitsev's rule

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