Advices For Studying Organic Chemistry

1. Sodium alkynides react with aldehydes and ketones to yield alcohols.

H 3 CC CH NaNH−NH 32 H 3 CC CNa

Na

CH 3

C

CH 3

H 3 CC C + O H 3 CC C

δ−

C H 3 CC C

CH 3

CH 3

ONa

δ+ H 3 O+

C

CH 3

CH 3

OH

12.9 LITHIUM DIALKYLCUPERATES: THE COREY-POSNER,

WHITESIDES-HOUSE SYNTHESIS

1. A highly versatile method for the synthesis of alkanes and other hydrocarbons
   from organic halides has been developed by E. J. Corey (Harvard University,
   Nobel Prize for Chemistry in 1990), G. H. Posner (The Johns Hopkins University),
   and by G. M. Whitesides (Harvard University) and H. O. House (Georgia Institute
   of Technology).
   R X + R' X seve(−ral s 2 Xteps) R R'

1) The transformation of an alkyl halide into a lithium dialkylcuprate (R 2 CuLi)

requires two steps:

i) The alkyl halide is treated with lithium metal in an ether solvent to give an

alkyllithium, RLi.

R X ++2 Li diethyl ether RLi LiX

Alkyllithium

ii) Then the alkyllithium is treated with cuprous iodide (CuI) to furnish the lithium

dialkylcuprate.

2 +CuI R 2 CuLi LiI

Alkyllithium Lithium dialkylcuprate

RLi +

2) One alkyl group of the lithium dialkylcuprate undergoes a coupling reaction with

the second alkyl halide (R’–X) to afford an alkane.