A. W. H. Jans

The meta photocycloaddition of anisole to oxa- and dioxa-cyclopentenes and to ethyl vinyl ether

Abstract The meta photocycloaddition of anisole to 2,3- and 2,5-dihydrofuran, 1,3-dioxole and ethyl vinyl ether is described. The NMR data of the adducts are presented. The reaction yields mixtures of endo and exo adducts. The endo/exo ratio is strongly influenced by the presence of one or two oxygen atoms next to the double bond of the alkene. A mechanism is presented in which a zwitterionic intermediate is formed from the excited anisole and the alkene.

The meta photocycloaddition of anisole and benzonitrile to 1,3-dioxol-2-one

Abstract The meta photocycloadditions of benzonitrile and anisole to 1,3-dioxol-2-one both yield two major products. In both cases the adducts are those which would be expected if some form of polar species were to develop along the reaction pathway. The absence of exo adducts in the case of benzonitrile and 1,3-dioxol-2-one is discussed.

The meta-photocycloaddition of ethylvinylether to 3-methylanisole and 3-fluoroanisole

Abstract Photoaddition of ethylvinylether to 3-methylanisole yields six derivatives of 1-methoxytricyclo[3.3.0.02,8]oct-3-ene. Four of the adducts have the ethoxy group in an endo position. Products in which the methyl group is at position 4 are favoured. Photoaddition of ethylvinylether to 3-fluoroanisole yields three isomeric adducts, to endo and one exo.

Photocycloaddition of ethylvinylether and cyclopentene to 3.5-dimethylanisole

Abstract Photocycloadition of ethylvinylether and cyclopentene to 3,5-dimethylanisole yields derivatives of 1-methoxy-2, 4-dimethyltricyclo [3.3.0.0 2,8 ]oct-3-ene in which the substituents at positions 6 and/or 7 are endo. Structural proofs are based on 250 MHz 1 H and 62.9 MHz 13 C NMR spectra.