Advices For Studying Organic Chemistry

Figure 8.C With increasing alkyl substitution of the bromonium ion, the lobe of
the LUMO where electron density from the nucleophile will be
contributed shifts more and more to the more substituted carbon.
2) In the bromonium ion of ethene (I), equal distribution of the LUMO lobe near

4) In

fr irtually none

8.9 D

1. Ca
   1 eeting

2) synthetic use in the preparation of

the two carbons where the nucleophile could attack.

3) In the bromonium ion of propene (II), the corresponding LUMO lobe has more

of its volume associated with the more substituted carbon, indicating that

electron density from the nucleophile will be best accommodated here.

the bromonium ion of 2-methylpropene (III) has nearly all of the volume

om this lobe of the LUMO associate with the 3° carbon and v

associated with the 1° carbon.

IVALENT CARBON COMPOUNDS: CARBENES

rbenes: compounds in which carbon forms only two bonds.

) Most carbenes are highly unstable compounds that are capable of only fl

existence.

The reactions of carbenes are of great

compounds that have three-membered rings.