Janey J M, Iwama T, Kozmin S A, Rawal V H
Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, USA.
J Org Chem. 2000 Dec 29;65(26):9059-68. doi: 10.1021/jo005619y.
Achiral and chiral 1-(2-oxazolidinon-3-yl)-3-siloxy-1,3-butadienes were prepared from readily available starting materials. Although more stable than the parent 1-amino-3-siloxy dienes, the 1-(2-oxazolidinon-3-yl)-3-siloxy-1,3-butadienes are still very reactive in Diels-Alder reactions, somewhat more than 1,3-dialkoxy-1, 3-butadienes (e.g., Danishefsky's diene). The cycloadditions of the achiral and chiral dienes with several different dienophiles were examined. The reactions proceeded in good yield, with modest to high endo selectivity. The chiral dienes exhibited excellent facial selectivity in cycloadditions with alpha-substituted acroleins, maleic anhydride and N-phenylmaleimide. Upon reduction and hydrolysis of the cycloadducts, substituted cyclohexenones were obtained with ee's ranging from 22% to >98%.
非手性和手性的1-(2-恶唑烷酮-3-基)-3-硅氧基-1,3-丁二烯由易得的起始原料制备而成。尽管1-(2-恶唑烷酮-3-基)-3-硅氧基-1,3-丁二烯比母体1-氨基-3-硅氧基二烯更稳定，但它们在狄尔斯-阿尔德反应中仍然非常活泼，比1,3-二烷氧基-1,3-丁二烯（如丹尼谢夫斯基二烯）稍活泼一些。研究了非手性和手性二烯与几种不同亲双烯体的环加成反应。反应产率良好，具有适度到较高的内向选择性。手性二烯在与α-取代丙烯醛、马来酸酐和N-苯基马来酰亚胺的环加成反应中表现出优异的面选择性。环加成产物经还原和水解后，得到了对映体过量值在22%至>98%之间的取代环己烯酮。
