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Chemoselective Lithiation of 1‐Bromo‐ n ‐chloroalkanes
Author(s) -
Foubelo Francisco,
Abou Abdeslam,
Yus Miguel
Publication year - 2005
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200500407
Subject(s) - chemistry , hydrolysis , bromine , lithium (medication) , chlorine , molar ratio , naphthalene , medicinal chemistry , organic chemistry , carbon fibers , catalysis , medicine , materials science , composite number , composite material , endocrinology
Reactions between different 1‐bromo‐ n ‐chloroalkanes ( 1 – 3 ), lithium/naphthalene (1:2 molar ratio) and a carbonyl compound R 1 R 2 CO in THF at –78 °C provide, after hydrolysis with water, the corresponding chlorinated alcohols 4 through selective lithiation of the carbon–bromine bond. When an excess of lithium (1:7 molar ratio) is added to the reaction mixture before the hydrolysis, lithiation of the remaining carbon–chlorine bond takes place. The addition of a second carbonyl compound R 3 R 4 CO, followed by hydrolysis, affords the corresponding diols 7 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)