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[摘要]：Sensitized photocycloaddition reactions of 6,6'-dimethyl-4,4' -[1,4-bis(methylenoxy)phenylene]-di-pyrone (1) with poly(ethyleneglycol)divinyl ethers (2a, b) or 2,2'-dimethyltrimethylene dimethacrylate (4), together with the reactions of 6,6'-dimethyl-4,4'-polymethylenedioxy-2-pyrones (6a, b) with 4 were described. The reactions of 1 with 2a, b gave crown ether type macrocyclic compounds (3a and 3a' (isomer of 3a), 3b and 3b' (isomer of 3b)) possessing 19- and 22-membered rings across the C3-C4 and C3'-C4' double bonds in 1, respectively. Similar reactions of 1 with 4 and 6a, b with 4 afforded different types of macrocycles (5 and 5', 7a, b and 7a', b') having 19- to 21-membered rings across the C5-C6 and C5'-C6' double bonds in 2-pyrone ring. The stereochemical features of 3a' and 5 were determined by X-ray crystal analysis. The reaction mechanism was inferred by MO methods. |
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