Diastereoselective Diels-Alder Reactions of 1,7,9-Decatrien-3-ones to Highly Substituted Octalin Derivatives

作者：Thiemermann Jutta; Schnaubelt Jurgen; Zimmer Reinhold; Reissig Hans Ulrich^*

来源：Synthesis (Germany), 2016, 48(24): 4533-4540.

DOI：10.1055/s-0036-1588323

• Diels-Alder reaction
• intramolecular cycloaddition
• Lewis acid
• diastereoselectivity
• titanium

Based on an efficient synthesis of 1,7,9-decatrien-3-one precursors we studied their thermal and Lewis acid-promoted intramolecular Diels-Alder reactions to octalin derivatives. Whereas the thermal cycloadditions showed only cis/trans selectivities close to 35: 65, the transformations were strongly influenced by the type of Lewis acid employed. With mono-coordinating Lewis acids such as BF3, cis/trans ratios of up to 85: 15 were observed, whereas di-coordinating Lewis acids such as TiCl2(OiPr)(2) induce fairly high trans-selectivity. This remarkable switch of diastereoselectivity is discussed.

• 出版日期2016-12