Me2AlCl, intramolecular Diels—Alder reaction

TABLE 5-7. Me2AlCl-Promoted Intramolecular Diels-Alder Reactions of Trienimides 138 and 141... 

They also reported the intramolecular version of this asymmetric Diels-Alder reaction [53]. ( , )-Trienecarboximides of type 45 derived from chiral oxazolidones undergo Me2AlCl-catalyzed intramolecular Diels-Alder reactions affording bicyclic compounds 46 with high endo and diastereoselectivity (endolexo = -100 1). The stereochemistry is controlled by the stereogenic center at C4 of the chiral auxiliary (Xc) (Sch. 29). 

The first total asymmetric synthesis of solanoeclepin A has been presented in 2011 by Tanino et al. [200]. It also features a Me2AlCl-catalyzed intramolecular Diels-Alder reaction as outlined in Scheme 26. Solanoeclepin A stimulates the hatching of potato cyst nematode, a parasite with destructive effect on several crops. One possible fight against this pest would be to induce early hatching of... 

Catalysis of Diels-Alder Reactions. Me2AlCl has been used as a Lewis acid caUilyst for inter- and intramolecular Diels-Alder reactions with a wide variety of dienophiles. High diastereoselectivity is obtained from chiral a,p-unsaturated N-ticyloxazolidinones with more than 1 equiv of Me2AlCl. Use of MezAlCl as a catalyst affords high yields in inter- and intramolecular Diels-Alder reactions of a,p-unsaturated ketones (eq 1), and intramolecular Diels-Alder reactions of a, 3-unsaturated aldehydes. Me2AlCl-catalyzed Diels-Alder reac-... 

The non-selective thermal Diels-Alder reaction of hexa-2,4-dienol with methyl acrylate is made enantioselective by using the Lewis acid template (86) to assemble the reagents for cycloaddition.91 The Me2AlCl-catalysed intramolecular Diels-Alder... 

Although a-siloxyacroleins 84, 87a, and 87b had been separately prepared via a retro-hetero-Diels-Alder reaction of dioxin derivatives such as 83, Aungst and Funk also showed that tandem Me2AlCl-mediated decomposition of the dioxin derivative 97 to the a-siloxyenal intermediate 98 and intramolecular cycloaddition could occur in one pot to give good yields of fused bicyclic adducts (Scheme 18.21) [23]. 

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