Electric Literature of 19132-06-0, Because a catalyst decreases the height of the energy barrier, its presence increases the reaction rates of both the forward and the reverse reactions by the same amount.19132-06-0, Name is (2S,3S)-Butane-2,3-diol, molecular formula is C4H10O2. In a article£¬once mentioned of 19132-06-0
Experiments Directed Towards the Synthesis of Anthracyclinones. XVI Tin(IV)- and Titanium(IV)-Mediated Cyclizations of ortho-Allyl-Substituted Homochiral Hydroxyanthraquinone Dioxolans
Tin(IV) chloride and titanium(IV) chloride mediated cyclizations of the ortho-allyl-substituted homochiral hydroxyanthraquinone acetals (7)-(10), prepared by optimized reductive Claisen rearrangements, have afforded monochloro and dichloro tetracyclic products, the stereochemistry of which has been assigned by using n.m.r. techniques.An SN2-like process in which the dioxolan ring is maintained as an ion pair intermediate is favoured when either tin(IV) chloride or titanium(IV) chloride is used at -78 deg.Thereafter the direction of addition of chloride at C9 is largely governed by the orientation of this ion pair.An alternative path which probably involves a free oxocarbenium ion predominates at higher temperatures.An adjacent methoxy group on the anthraquinone lowers the stereoselectivity at both C7 and C9, possibly by bidentate coordination of the Lewis acid involving the quinone carbonyl, the methoxy oxygen and the acetal oxygens.
A reaction mechanism is the microscopic path by which reactants are transformed into products. Each step is an elementary reaction. 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