Diastereoselective Additions of Enantioenriched (γ-Alkoxyallyl)stannanes to α-Alkoxy Aldehydes: A Synthetic Route to Carbohydrates

Article abstract of DOI:10.1021/jo00002a001

BF3*OEt2-promoted additions of the (S)-(γ-alkoxyallyl)stannane 3-(S) to the (R)-α-alkoxy aldehydes 13 and 18 affords the syn adducts 14 and 19 with greater than 90:10 diastereoselectivity.With MgBr2 as the catalyst addition to the (S)-α-alkoxy aldehyde 4 is most selective (97:3) with the (S)-(γ-alkoxyallyl)stannane 3-(S) whereas BF3-promoted addition to 4 is most selective (92:8) with the R enantiomer 3-(R).