Highly anti-selective SN2′ substitutions of chiral cyclic 2-iodo-allylic alcohol derivatives with mixed zinc-copper reagents

[GRAPHICS] Functionalized allylic electrophilic reagents such as chiral 2-iodo-1-cyclohexenyl and -cyclopentenyl phosphates undergo highly stereoselective ant S(N)2'-allylic substitution reactions with a wide range of organozinc reagents (R2Zn and RZnl) 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 greater than or equal to93% ee.