Enantioselective Synthesis of (-)-(7a<i>S</i>)-2,3,7,7a-Tetrahydro-7a- phenylthio-1<i>H</i>-indene-1,5(6<i>H</i>)-dione and (+)-(8a<i>S</i>)-3,4,8,8a-Tetrahydro-8a-phenylthio-1,6(2<i>H</i>,7<i>H</i>)-naphthalenedione
作者:Stefan Kwiatkowski、Ashfaq Syed、Carolyn P. Brock、David S. Watt
DOI:10.1055/s-1989-27400
日期:——
Application of the Hajos-Parrish asymetrically biased aldol condensation to 2-(3-oxobutyl)-2-phenylthio-1,3-cyclopentanedione (5a) or 2-(3-oxobutyl) -2-phenylthio-1,3-cyclohexanedione (5b) using (R)-(+)-proline provided (-)-(7aS)-2,3,7,7a-tetrahydro-7a-phenylthio-1H-indene -1,5(6H)-dione (7a) and (+)-(8aS)-3,4,8,8a-tetrahydro-8a -phenylthio-1,6(2H,7H)-naphthalenedione (7b), respectively, in ≥ 95% enantiomeric excess, as determined by 1H-NMR analysis using tris[3-heptafluoropropylhydroxymethylene)-(+)-camphorato]europium(III).
使用(R)-(+)-脯氨酸对 2-(3-氧代丁基)-2-苯硫基-1,3-环戊二酮(5a)或 2-(3-氧代丁基)-2-苯硫基-1,3-环己二酮(5b)进行 Hajos-Parrish 不对称偏置醛醇缩合,可得到(-)-(7aS)-2,3,7,7a-四氢-7a-苯硫基-1H-茚-1、5(6H)-二酮(7a)和(+)-(8aS)-3,4,8,8a-四氢-8a-苯硫基-1,6(2H,7H)-萘二酮(7b),对映体过量率≥95%。