Irradiation at low temperatures (0 degreesC) of alkyl-, aryl- and styryl al
koxychromium(0)carbene complexes in the presence of methyl acrylate produce
s a mixture of diastereomeric cyclopropanes and C-H insertion derivatives.
The ratio cyclopropane/C-H insertion product is independent of the reaction
conditions, while the cyclopropane cis:trans ratio strongly depends on the
solvent, the selectivity increasing as the polarity of the reaction solven
t does. (C) 2001 Elsevier Science Ltd. All rights reserved.