Asymmetric Allylation of Carbonyl Compounds with Tartrate-Modified Chiral Allylic Tin Reagents

Article abstract of DOI:10.1246/bcsj.70.2301

Chiral allylating reagents, readily generated in situ from tin(II) catecholate [Sn^II(O₂C₆H₄)], allyl halides, chiral dialkyl tartrates, and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), reacted smoothly with aldehydes or reactive ketones at - 78 °C in the presence of a catalytic amount of copper salts to afford the corresponding optically active homoallyl alcohols. Allylation of aromatic aldehydes and pyruvates by the present chiral tin reagents proceeded in high yields (81-99%) with high enantioselectivities (89-94%ee). In addition, both enantiomers of dimethyl citramalate were prepared from the allylation products of benzyl pyruvate.