1252014-05-3Relevant articles and documents
1, 5-and 1, 3-photocyclization reactions of 8substituted-l,2,3,4- tetrahydro-1naphthalenones
Sharshira, Essam Mohamed
experimental part, p. 369 - 376 (2010/08/20)
Photocyclization reactions were carried out on 8-(4-halobenzyloxy)-l,2,3,4- tetrahydro-l-naphmalenones (halogen = Cl and Br in 1a and 1b respectively), 8-(4-nitrobenzyloxy)-l,2,3,4-tetrahydro-l-naphthalenone 1c and 8oxo-5,6,7,8-tetrahydro-l-naphthyloxyacetonitrile 1d in benzene. Irradiation of 1a-b afforded rearranged naphthyl alcohols (1,3-cyclization products) 4a-b and naphmo[l, 8-bc]furanol derivatives (1,5-cyclization products) 2a-b. On the omer hand, irradiation of 1c-d under the same condition afforded only 1,5-cyclization producsts 2c-d in each case. Different behaviours for me photoreaction of 1a-b and for 1c-d is attributed to me stability of me 1, 5-biradical intermediates formed by δ-hydrogen abstraction. Substituent effects in cyclization step of 1,5-biradicals are discussed along with reaction pathways.