The presence of a removable 1-(trimethylsilyl) residue greatly increases the chelation-controlled diastereoselectivity in alkenylcuprate additions to chiral beta-alkoxyaldehydes. Several methods for protiodesilylation of the resultant allylic alcohols [5 --> 2b (R = Me3SiCH2CH2OCH2-, PhCH2OCH2-, and PhCH2-)T are compared.