Bifunctionalized allenes. Part XXII. Coinage metal-catalyzed cycloisomerization of phosphorylated 3-(α- or β-hydroxyalkyl)allenes to 2-phosphoryl-2,5-dihydrofurans or 2-phosphoryl-5,6-dihydro-2H-pyrans

Stereoselective preparation of P,axial-stereogenic allenyl bisphosphine oxides via chirality-transfer

P,C-Stereogenic propargyl alcohols RC-3/SC-3' were prepared by the addition of (L)-menthyl-derived SPOs to propynals, which were converted to P,axial-stereogenic allenyl bisphosphine oxides. The chirality transfer was controlled by α-carbon via syn [2,3]-sigmatropic rearrangement. For SC-3' linking weak WDG on the alkynyl moiety, the chirality on the axis depended on stereogenic phosphorus.