Highly anti-selective SN2' substitutions of chiral cyclic 2-iodo-allylic alcohol derivatives with mixed zinc-copper reagents.
[reaction: see text] Functionalized allylic electrophilic reagents such as chiral 2-iodo-1-cyclohexenyl and -cyclopentenyl phosphates undergo highly stereoselective anti-S(N)2'-allylic substitution reactions with a wide range of organozinc reagents (R(2)Zn and RZnI) leading to chiral products with a transfer of the chiral information >95%. The use of functionalized organozinc iodides allows preparation of the bicyclic enones 8 and 9 in >or=93% ee.
Calaza
M Isabel
MI
Department Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany.
Hupe
Eike
E
Knochel
Paul
P