Electric Literature of 19132-06-0, A catalyst don’t appear in the overall stoichiometry of the reaction it catalyzes, but it must appear in at least one of the elementary reactions in the mechanism for the catalyzed reaction. 19132-06-0, Name is (2S,3S)-Butane-2,3-diol, molecular formula is C4H10O2. In a Article£¬once mentioned of 19132-06-0
Mechanistic Studies of Diastereoselective Cyclopropanation via Homochiral Ketals. 1. Dioxolane Structural Effects
Compounds structurally related to 2-cyclohexen-1-one 1,4-di-O-benzyl-L-threitol ketal were prepared and subjected to the Simmons-Smith cyclopropanation.From these experiments a mechanistic model for diastereoselective cyclopropanation of common ring systems (five-, six-, and seven-membered) has been formulated.Diastereoselectivity is thought to result from preferential chelation of the Simmons-Smith reagent at the least sterically hindered lone pair of electrons on the dioxolane oxygen proximal to the alkene.It is found that the presence of oxygen atoms in the dioxolane appendages provide sites for competitive chelation of the reagent, which can antagonize the diastereoselection due to chelation at dioxolane oxygen.That chelation by dioxolane oxygen does occur and is responsible for diastereoselectivity is inferred from studies with a hydrocarbon model system.Surprisingly, both dioxolane appendages are shown to be necessary for optimum diastereoselection since, under the conditions of the Simmons-Smith cyclopropanation, 2-cycloalken-1-one ethylene ketals are reversibly ring opened to zwitterionic intermediates.
Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.Electric Literature of 19132-06-0. In my other articles, you can also check out more blogs about 19132-06-0
Reference£º
Synthesis and Crystal Structure of a Chiral?C3-Symmetric Oxygen Tripodal Ligand and Its Applications to Asymmetric Catalysis,
Chiral lanthanide(III) complexes of sulphur¨Cnitrogen¨Coxygen ligand derived from aminothiourea and sodium?D-camphor-¦Â-sulfonate