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Stereospecific Construction of Chiral Tertiary and Quaternary Carbon by Nucleophilic Cyclopropanation with Bis(iodozincio)methane
Author(s) -
Nomura Kenichi,
Matsubara Seijiro
Publication year - 2010
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.200900289
Subject(s) - ketone , chemistry , alkoxide , nucleophile , electrophile , cyclopropanation , cyclopropane , stereospecificity , medicinal chemistry , organic chemistry , ring (chemistry) , catalysis
The reaction of a ketone having a leaving group at the α‐position, such as α,β‐epoxy ketone or α‐sulfonyloxy ketone, with bis(iodozincio)methane affords a zinc alkoxide of cyclopropanol. The reaction proceeds by nucleophilic addition of the dizinc to the carbonyl group and a sequential intramolecular nucleophilic substitution of the introduced iodozinciomethyl group to the adjacent electrophilic carbon that has a leaving group. When an optically active α,β‐epoxy ketone or α‐sulfonyloxy ketone is treated with the dizinc, a zinc alkoxide of cyclopropanol having a chiral tertiary or quaternary carbon in the cyclopropane ring is obtained, and the obtained zinc alkoxide of cyclopropanol acts as a chiral homoenolate. When it is treated with an electrophile in the presence of copper cyanide, it gives an optically active α‐tertiary or ‐quaternary ketone that retains high optical purity.