Process for the production of (−) 3,4-divanillyl tetrahydrofuran

This invention relates to a process for the production of (−) 3,4-divanillyl tetrahydrofuran. More particularly, this invention relates to an improved process for the isolation of (−) secoisolariciresinol from the heart wood and roots of and conversion of (−) secoisolariciresinol of formula (1) into its semisynthetic analog (−) 3,4-divanillyl tetrahydrofuran of formula (2). The present invention relates to a process for the production of (−)3,4-divanillyl tetrahydrofiran of formula (2) which comprises (a) isolating) (−) secoisolariciresinol of formula (1) from the heartwood and roots of by an improved process which consists of partitioning of the alcoholic extract of the heartwood and roots of between water and chlorinated solvent, (b) extracting the chlorinated solvent extract with alkali and (c) isolating (−) secoisolariciresinol from the alkali extract upon neutralization with mineral acid and extracting with organic solvent and (d) crystallizing it from suitable organic solvent, (e) dissolving the isolated (−) secoisolariciresinol in suitable organic solvent and (f) reacting with triphenyl phosphine halide at 0-80° C. for 1-10 hours and (g) isolating (−) 3,4-divanillyl tetrahydrofuran by column chromatography.