Concerning reversal of diastereoselectivity in the BF3 promoted addition of crotyl-organometallic compounds to aldehydes

Article abstract of DOI:10.1016/0022-328X(85)80039-5

The addition of a mixture of benzaldehyde and BF₃·OEt₂ to crotyl-organometallic reagents C₄H₇MLn (1) (M = Cu, Cd, Hg, Tl, Ti, Zr and V) produces predominantly the erythro homoallyl alcohol as well as the α-adduct, while without BF₃·OEt₂ the threo isomer is formed preferentially.