Question

Couple questions regarding basic alkene reaction mechanisms. (1) In reactions such as hydroboration, how do reagants such as H2O2, OH- (hydroboration) replace BH2 that bonds and makes the first intermediate (2) How does bridge breaking and the grabbing of OsO4 in hydroxylation of cycloalkenes work? I dont see how you can break a double bond and grab the oxygens of OsO4 when it is neutral and octet happy? (3) What types of reactions normally produce racemic mixtures? (4) what does a reagant such as CCl4 do in halogenation along with X2 (halogen addition) ?

Answer 1

3. chiral molecule have a single stereogenic (chiral centere) carbon atom, which has four different group or atom substituents. the chiral molecules produce recemica mixtures. These two enantiomers are compounds have different absolute configurations at this center.like one R the other S configarations. chiral molecules different addtion or substitution reactions produces racemic mixture products, a molecule at any center attached four different groups or atoms.

4.The halogenation X₂ reagent with CCl₄ is no reaction. CCl4 is mainly inert solvent that will not react with either the X₂, or product . It is simply work as medium for the reaction.