Oppolzer synthesis

For reviews of Diels-Alder reactions of some of these compounds, sec Charlton Alauddin Tetrahedron 1987, 43, 2873-2889 Oppolzer Synthesis 1978, 793-802,... 

W. Oppolzer, Synthesis, 793 (1978). has reviewed iniramolecular cycloaddilion reactions of o-quinodimethancs. 

Intramolecular Cycloaddition Reactions of ortho-Quinodimethanes in Organic Synthesis W. Oppolzer, Synthesis, 1978, 793-802. 

Felkin product (69% ds, 2-anti). A (Z)-titanium enolate usually favours the anti-Felkin adduct, and the subsequent Oppolzer synthesis of denticulatins A (see Scheme 9-69) highlights this behaviour (see also Scheme 9-30) however, exceptions can be found (Scheme 9-45). Oxidation of the C3 and Cn hydroxyls of 258, and cyclization, under carefully controlled conditions to preserve the configuration of the Cio stereocenter, then allowed the selective synthesis of denticulatin B. 

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