Stereoselective functionalization of cyclopropane derivatives using bromine/magnesium and sulfoxide/magnesium exchange reactions.
The reaction of 2,2-dibromo-1-methyl-cyclopropanecarbonitrile (1) with i-PrMgCl in Et(2)O/CH(2)Cl(2) provides the cis-magnesium-carbenoid (2), which reacts with high retention of configuration with various electrophiles. If E = SPh, a stereoselective generation of a quaternary center via a sequential Br/Mg- and sulfoxide/Mg-exchange can be achieved. [reaction: see text]
Kopp
Felix
F
Department Chemie und Biochemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 Munich, Germany.
Sklute
Genia
G
Polborn
Kurt
K
Marek
Ilan
I
Knochel
Paul
P