What is Lemieux Johnson reagent?

The conversion of an olefin into two individual aldehydes by means of an oxidative cleavage of a carbon-carbon double bond with osmium tetraoxide-sodium periodate is known as the Lemieux–Johnson oxidative cleavage and the combination of osmium tetraoxide and sodium periodate is referred to as Lemieux–Johnson reagent.

What does OsO4 do in a reaction?

In organic synthesis OsO4 is widely used to oxidize alkenes to the vicinal diols, adding two hydroxyl groups at the same side (syn addition). See reaction and mechanism above. This reaction has been made both catalytic (Upjohn dihydroxylation) and asymmetric (Sharpless asymmetric dihydroxylation).

What is periodate cleavage?

Periodate cleavage is often utilized in molecular biochemistry for the purposes of modifying saccharide rings, as many five- and six-membered sugars have vicinal diols. Historically it was also used to determine the structure of monosaccharides.

Is NaIO4 an oxidizing agent?

Organic Chemistry Sodium periodate (NaIO4), is a strong oxidizing agent mainly used for the oxidative cleavage of 1,2-diols (vicinal diols) forming aldehydes and ketones depending on the structure of the alcohol.

What is Malaparade reagent?

From Wikipedia, the free encyclopedia. In organic chemistry, the Malaprade reaction or Malaprade oxidation is a glycol cleavage reaction in which a vicinal diol is oxidized by periodic acid or a periodate salt to give the corresponding carbonyl functional groups.

What is NaIO4?

NaIO4 is used in organic chemistry to cleave diols to produce two aldehydes.

Is osmium tetroxide a fixative?

Osmium Tetroxide is traditionally used in electron microscopy both as a fixative and a heavy metal stain. Osmium Tetroxide is a good fixative and excellent stain for lipids in membranous structures and vesicles. The most prominent staining in adherent human cells (HeLa) is seen on lipid droplets.

What is naio4?

What is io4?

Description. Periodate is a monovalent inorganic anion obtained by deprotonation of periodic acid. It is a monovalent inorganic anion and an iodine oxoanion. It is a conjugate base of a periodic acid. ChEBI.

Is naio4 toxic?

This substance is a strong oxidising agent and is very toxic. It is an eye and skin irritant. If irritation or pain persist seek medical attention. Ingestion wash out the mouth thoroughly with water and give water or milk to drink.

What is HIO4?

Reaction type: Oxidation-reduction 1,2- or vicinal diols are cleaved by periodic acid, HIO4, into two carbonyl compounds. The reaction is selective for 1,2-diols. The reaction occurs via the formation of a cyclic periodate ester (see right). This can be used as a functional group test for 1,2-diols.

Is OSO4 ionic or covalent?

Osmium tetroxide is an osmium coordination entity consisting of four oxygen atoms bound to a central osmium atom via covalent double bonds.

What is Lemieux-Johnson reagent?

The conversion of an olefin into two individual aldehydes by means of an oxidative cleavage of a carbon‐carbon double bond with osmium tetraoxide‐sodium periodate is known as the Lemieux–Johnson oxidative cleavage and the combination of osmium tetraoxide and sodium periodate is referred to as Lemieux–Johnson reagent.

What is the name of the reaction given to Lemieux?

The reaction is named after its inventors, Raymond Urgel Lemieux and William Summer Johnson, who published it in 1956. The reaction proceeds in a two step manner, beginning with dihydroxylation of the alkene by osmium tetroxide, followed by a Malaprade reaction to cleave the diol using periodate.

What is the difference between ozonolysis and Lemieux Johnson reaction?

The Lemieux–Johnson reaction ceases at the aldehyde stage of oxidation and therefore produces the same results as ozonolysis . The classical Lemieux–Johnson oxidation often generates many side products, resulting in low reaction yields; however the addition of non-nucleophilic bases, such as 2,6-lutidine, can improve on this.