Total Synthesis Of Some Naturally Occurring Lignans And Studies On Cross-coupling Reactions Of Some Phenylpropanoids

This thesis mainly focused on both the synthesis of a few naturally occurring lignans and the regioselective oxidative cross-coupling of phenylpropanoids, including the following three parts:Chapter 1. Total synthesis of (±)-Matairesinol and (±)-Secoisolariciresinolβ-β dimeric product was obtained from the oxidative coupling of the precursor by FeCl₃/O₂ which was introduced a t-Bu as a position protecting group. Then, (±)-Matairesinol and (±)-Secoisolariciresinol, belonging to dibenzylbutyrolactone and dibenzylbutanediol lignans respectively, were synthsesized through other several steps, such as hydrogenation, reduction and the removal of t-Bu.Chapter 2. Study on total synthesis of Anolignan Bβ-β dimeric product was produced regioselectively utilizing the same strategy. Anolignan B, a dibenzylbutadiene lignan was expected to be obtained by the steps of hydrogenation, removal of t-Bu and other groups transformations. But we have encountered a problem at the last step and it remains to be resolved.Chapter 3. Primary study of oxidative cross - coupling of phenylpropanoidsBy introducing a t-Bu to coupling precursor as a position protecting method, the mixture of phenylpropanoids having different substituents were oxidized, expected to get naturally occurring lignans substituted by different aromatic groups. Three cross-coupling products possessing different skeleton structure have been obtained, and the structure of the one of which needs further identification.This thesis concerns both the total synthesis of some naturally occurring lignans in higher yield than previous similar method by introducing a t-Bu to coupling precursor as position protecting group, and a initial study of regioselectively oxidative cross -coupling of phenylpropanoids. The structures of all new compounds were identified by spectral analysis.