FIGR ID=ol702876rn00002>journals/orlef7/10/i02/figures/ol702876rn00002.gif" ALIGN="left" HSPACE=5> |
A novel chromium-promoted alkyl- and silyl cyclopropanation o
f (
E)- or (
Z)-
ges/
gi
fchars/alpha.
gi
f" BORDER=0>,
ges/
gi
fchars/beta2.
gi
f" BORDER=0 ALIGN="middle">-unsaturated amides in which the C-C double bond is di-, ortrisubstituted is described. This process takes place with total stereospeci
ficity, and the new stereo
genic center is
generated with hi
gh or totalstereoselectivity. A mechanism is proposed to explain the cyclopropanation reaction.