Orgo Prelim #2 Material

more stable formation (E vs. Z)

E, larger groups are more spread apart

Addition of Halides

H goes on C with a smaller number of alkyl substituents

X bonds to C with more alkyl subsituents

• if there is excess and an alkyne is present, the 2 X will go on the SAME carbon (more subsituents)

what is an intermediate carbon?

carbocation (2 prime is carbon bonded to 2 carbons). A tertiary carbocation is more stable (groups help with the positive charge)

Hydrations of Alkenes

Addition of an OH (often shown as H3O+)

• alkeenes → alcohols 

Pt/C catalyst (or Pd/C)

alkene to alkane adding 2 hydrogens

lindlar cataliyst

Alkyne → cis alkene

• ALWAYS cis formation

hydroboration-oxidation 

• BH3. The B goes on the less substituted carbon (less EN than H) and is then later substituded by an OH

1. BH3/THF

2. H2O2, -OH

oximercuration-reduction

OH on the MORE substituted C.

1. Hg(OAc)2/H2O

2. NaBH4/NaOH

ozonolysis to form aldehyde + ketone

forms a aldehyde and a ketone

1. O3

2. (CH3)2S

ozonolysis to form carboxylic acid

H2O2 + H2O causes aldehydes to become carboxylic acids 

hydration of alkynes

alkynes form ketones

• hg2+, H2SO4

hydroboration with alkynes

1. Bh3 -THF

2. H2O2, -OH

alkynes → ketone