Aversa M C, Barattucci A, Bonaccorsi P, Giannetto P, Policicchio M
Dipartimento di Chimica organica e biologica, Università degli Studi di Messina, Salita Sperone 31 (vill. S. Agata), 98166 Messina, Italy.
J Org Chem. 2001 Jul 13;66(14):4845-51. doi: 10.1021/jo015595a.
The addition of enantiopure sulfenic acids to oxoalkynes constitutes a new and efficient methodology for the synthesis of beta-sulfinyl alpha,beta-unsaturated carbonyl compounds. Sulfenic acids 3 and 4 were generated by thermolysis of suitable precursors and trapped in situ by oxoalkynes 5, affording (R(S),E)- and (S(S),E)-3-alkylsulfinyl-1-phenyl-2-propen-1-ones, 4-alkylsulfinyl-3-buten-2-ones, and 3-[(1S)-isoborneol-10-sulfinyl]-2-propenoates 6 and 7 in good yields and in enantiomerically pure form after simple column chromatography. (R(S),E)-3-[(1S)-isoborneol-10-sulfinyl]-1-phenyl-2-propen-1-one (6(R)a) was involved as a heterodiene in inverse-electron-demanding Diels-Alder reactions with readily available electron-rich dienophiles 14 and 15, corroborating in each case the sulfinyl auxiliary capability in controlling the stereochemical outcome of these cycloadditions. Furthermore, the addition of methylmagnesium iodide to the carbonyl moiety of 6(R)a demonstrated that the chiral sulfur atom exerts a remote stereocontrol in this reaction if assisted by the hydroxy group being part of the isoborneol substituent.
将对映体纯的亚磺酸添加到氧代炔烃中，构成了一种合成β-亚磺酰基α,β-不饱和羰基化合物的新型高效方法。亚磺酸3和4通过合适前体的热解生成，并原位被氧代炔烃5捕获，经简单柱色谱后，以良好的产率和对映体纯的形式得到(R(S),E)-和(S(S),E)-3-烷基亚磺酰基-1-苯基-2-丙烯-1-酮、4-烷基亚磺酰基-3-丁烯-2-酮以及3-[(1S)-异冰片-10-亚磺酰基]-2-丙烯酸酯6和7。(R(S),E)-3-[(1S)-异冰片-10-亚磺酰基]-1-苯基-2-丙烯-1-酮(6(R)a)作为异二烯参与了与易于获得的富电子亲双烯体14和15的逆电子需求Diels-Alder反应，在每种情况下都证实了亚磺酰基助剂在控制这些环加成反应的立体化学结果方面的能力。此外，将甲基碘化镁添加到6(R)a的羰基部分表明，如果由作为异冰片取代基一部分的羟基辅助，手性硫原子在该反应中会发挥远程立体控制作用。
