Total Synthesis of Leukotrienes from Butadiene

Synthetic applications of chiral unsaturated epoxy alcohols prepared by sharpless asymmetric epoxidation

An overview of the synthesis and applications of chiral 2,3-epoxy alcohols containing unsaturated chains is presented. One of the fundamental synthetic routes to these compounds is Sharpless asymmetric epoxidation, which is reliable, highly chemoselective and enables easy prediction of the product enantioselectivity. Thus, unsaturated epoxy alcohols are readily obtained by selective oxidation of the allylic double bond in the presence of other carbon-carbon double or triple bonds. The wide availability of epoxy alcohols with unsaturated chains, the versatility of the epoxy alcohol functionality (e.g. regio- and stereo-selective ring opening; oxidation; and reduction), and the arsenal of established alkene chemistries, make unsaturated epoxy alcohols powerful starting materials for the synthesis of complex targets such as biologically active molecules. The popularization of ring-closing metathesis has further increased their value, making them excellent precursors to cyclic compounds.

Efficient and selective telomerization of 1,3-butadiene with diols catalyzed by palladium-carbene complexes

The selective telomerization of 1,3-butadiene with seven different linear and cyclic diols proceeds in the presence of in situ generated palladium carbene catalysts. By applying optimized reaction conditions, including very low metal loadings (2-10 ppm), excellent catalyst turnover numbers (>250,000) and good chemoselectivities are observed with respect to the mono-octadienyl ether derivatives. This protocol allows the efficient preparation of unsaturated alcohols, which are useful for various applications.