T. Ibata, J. Toyoda
Jun 1, 1985
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0
Influential Citations
17
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
Cyclic orthoester type 1,3-dipolar cycloadducts of 1-methoxy-2-benzopyrylium-4-olate with carbonyl compounds were obtained in high yields in the copper(II) acetylacetonate-catalyzed decomposition of o-methoxycarbonyl-α-diazoacetophenone in the presence of carbonyl compounds such as substituted benzaldehydes, acetaldehyde, propionaldehyde, isobutyraldehyde, pivalaldehyde, acetone, methyl ethyl ketone, methyl isopropyl ketone, 1,3-dichloroacetone, substituted acetophenones, benzoyl cyanides, cyclopentanone, cyclohexanone, 1-indanone, 9-fluorenone, anthrone, and anthraquinone. However, methyl t-butyl ketone, benzophenone, and xthanthone gave no adduct. Aldehydes and asymmetric ketones gave endo- and exo-adducts. The regiochemistry and stereochemistry of the adducts of aldehydes were determined on the basis of their coupling constants of methine protons. The reactions of p-methoxyphenyl o-diazoacetylbenzoate also gave similar 1,3-dipolar adducts. When carbonyl compounds of medium reactivity were used as a sub...