V. Capriati et al., Azaenolates of 2-chloromethyl-4-methoxymethyl-5-phenyl-2-oxazoline - A highly diastereo- and enantioselective synthesis of oxazolinyloxiranes, EUR J ORG C, (11), 2001, pp. 2035-2039
The oxazoline-derived titanium azaenolate 6 couples highly stereoselectivel
y with aldehydes affording highly optically pure oxazolinyloxiranes 7. The
epoxide 7a has been deblocked to form the optically pure formyl oxirane 9.
In contrast, the corresponding boron azaenolates 2 and 3 couple with very p
oor or no stereoselectivity. Lithium, aluminum and tin azaenolates have als
o been shortly studied.