Exam 3 Reactions

alkyl halide usually 3°, or 2° with stronger conditions

• halogen leaves • C+ rearrangement • weak base deprotonates beta H; H e- make alkene

good ionizers - water, alcohol

rate = k[RX]

weak small yields Zaitsev product bulky yields Hofmann product

Sn1

heat

anticoplanar if cyclohexane, X and H must both be axial

alkyl halide usually 2° or 3°

rate = k[RX][B]

• strong • nonpolarizable • matched with solvent • small (for Zaitsev product) • large (for Hofmann product)

• polar protic solvent • heat

2 “wedges” end up one one side of alkene (longways)

an alcohol

• hydroxy attacks H of acid to make a good LG • C-O bond breaks and water leaves • C+ rearrangement • water attacks & removes beta H - H e- form alkene

2° and 3° alcohol required phosphoric/sulfuric acid

• acid attacks hydroxy to make good LG • water leaves, and water attacks beta H - H e- make alkene

1° alcohol concentrated H2SO4

alkene

• alkene attacks H (or other electrophile), splitting it from X • C+ rearrangement • X attacks C+

alkyl halide pair of enantiomers

organic peroxide rxn HBr RO-OR solvent radical mechanism

terminal alkyne yields vinyl halides or geminal dihalides (depends on molar ratio) internal alkyne yields 4 products, no Markovnikov application

vinyl halide alkene