The reaction of trialkylvinylborates with aldehydes as applied to syntheses of 1,3-alkanediols, 1-chloro-3-heptanol and a cyclopropane derivative

Treatment of R'CHO with Li[R₃BCHCH₂] gives an adduct which is believed to be R₂BCHR-CH₂-CH(OLi)R' (2) or its borate form (3). Oxidation of the adducts with alkaline hydrogen peroxide gives ca. 1:1 mixture of diastereomeric 1,3-alkanediols in good yields. On the other hand, the reaction of BrMg[R₃BCHCH₂] with R'CHO affords less satisfactory results. Successive treatment of 2 (R = n-Bu, R' = H) with PCl₅ and alkaline H₂O₂ gives HOCHBu-CH₂-CH₂Cl (6). Treatment of Et₂BCHEt-CH₂-CHCl-Ph with NaOH aq produces l-ethyl-2-phenylcyclopropane 7.