Cm. Timmers et al., RHODIUM(II) CATALYZED ASYMMETRIC CYCLOPROPANATION OF GLYCALS WITH ETHYL DIAZOACETATE, Tetrahedron : asymmetry, 7(1), 1996, pp. 49-52
Carbenoid species generated from ethyl diazoacetate and catalytic Rh-2
(OAc)(4) react smoothly and with a high degree of stereoselectivity wi
th glycals resulting in the predominant formation of doubly branched a
dducts containing an alpha-exo-orientated ethyl cyclopropanecarboxylat
e moiety.