Synthesis of racemic Anti-1,3-diols: Complementarity between barluenga reduction and aldol-tishchenko reaction

Propionates are molecules with alternating hydroxyl and usually methyl groups along their carbon chain. The 1,3-diol motif is ubiquitous in most plant-derived molecules. These molecules generally possess remarkable biological properties. Given their importance, several synthetic methods exist, including the double reduction of diketones (Barluenga) and the Tischenko aldol condensation. By applying these two methods, fifteen diols were synthesized, including six C2-pseudo-symmetric diols by Barluenga reduction with a very good yield (60 to 77%) and very remarkable diasereoselectivities (dr= 75:25 to 98:02) and nine other molecules by Tischenko aldolization, including two pseudo-symmetric diols, with good diasereoselectivities (58:42 to 97:03) and moderate yields (14 to 68%). Diastereoselectivity is determined by integrating the proton spectrum of the unpurified product.