Asymmetric synthesis of a lignan lactone from a Meso anhydride

Stereoselective Anhydride Openings

“…Since 2007 she has been working with Professor Bolm and Professor Raabe, being involved in the determination of the absolute configuration of organic molecules by means of theoretical investigations and CD spectroscopy. step synthesis of optically active (1R,3S)-cis-chrysanthemic acid (12) starting from lactone 6b (eq 1).…”

“…Ward described the desymmetrization of a meso-2,3dibenzylbutanedioic acid anhydride with (R)-1-phenylethylamine, the corresponding amide acid being obtained as white crystals in 62% yield and 86% de. 12 Table 1. Anhydride Desymmetrization with (R)-2-Amino-2-phenylethanol entry anhydride imide yield (%) lactone yield (%) a ee (%) The desymmetrization of endo-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride using proline esters as chiral nucleophiles was reported by Noth.…”

“…Ward described the desymmetrization of a meso -2,3-dibenzylbutanedioic acid anhydride with ( R )-1-phenylethylamine, the corresponding amide acid being obtained as white crystals in 62% yield and 86% de …”

Practical and Highly Enantioselective Ring Opening of Cyclic Meso-Anhydrides Mediated by Cinchona Alkaloids

“…Desymmetrization of meso -compounds is an efficient strategy in asymmetric synthesis, because it allows to control the generation of multiple stereogenic centers in a single step . For example, starting from symmetrically substituted diesters or anhydrides, desymmetrization with the help of enzymes or chiral reagents provides dicarboxylic acid monoesters which are easily transferred to other versatile chiral building blocks for numerous synthetic applications (Scheme ) 1 …”