Asymmetric Synthesis of (1,3-Butadien-2-yl)methanols from Aldehydes via [1-(Silylmethyl)allenyl]methanols

[1‐(Silylmethyl)allenyl]methanols 2 were efficiently synthesized from aldehydes and (4‐bromobut‐2‐ynyl)trimethylsilane in the presence of a catalytic amount of CrCl2 and tridentate carbazole ligands. The desired compounds were obtained with good yields (43–88 %) and enantioselectivities (55–78 % ee). Alcohols 2 may be treated with TBAF or 2 M HCl in the case of aliphatic substrates, to provide (1,3‐butadien‐2‐yl)methanols 3 in 43–81 % yields. This method allows the synthesis of dienes 3 with no regioselectivity problems, and it tolerates a large number of functionalities. An asymmetric synthesis of (1,3‐butadien‐2‐yl)methanols is described. The method consists of an asymmetric Cr‐catalyzedaddition of a silylpropargyl bromide to avariety of aldehydes to obtain enantioenriched [1‐(silylmethyl)allenyl]methanols, which then undergo desilylation/isomerization to deliver the desired nonracemic (1,3‐butadienyl)methanol products.