Diels-alder stereo- and regioselectivity controlled by remote substituents and solvent. Cycloadditions of 1-(dimethoxymethyl)-2,3-bis(methylene)-7-oxabicyclo[2.2.1]Heptane

✍ Scribed by Jean-Luc Métral; Pierre Vogel

• Publisher: Elsevier Science
• Year: 1984
• Tongue: French
• Weight: 131 KB
• Volume: 25
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)91291-2

✦ Synopsis

T7ze regioseZectivity of the EtAlCZ -cataZyzed addition of methyl vinyl ketone to the titZe diene can be reversed by solvent modz &cation. 9

The chemical properties of the diene moieties in 2,3-bis(methylene)bicycloC2.2.l]alkanes can be affected by remote substitution at C(5) and C(6).' For example, the Diels-Alder additions of l2 and 2" are "para" regioselective, whereas those of 3 2 and 4 4 are "meta" regiose-lective. This type of long-range substituent effect has been applied in the synthesis of anthracyclinones.

132 We report here the cycloadditions of diene 5 whose stereo-and regioselec-