{"product_id":"photoswitchable-nine-membered-cyclic-enediynes-and-enyne-allenes-von-dinesh-pandithavidana","title":"PHOTOSWITCHABLE NINE-MEMBERED CYCLIC ENEDIYNES AND ENYNE-ALLENES","description":"\u003cp\u003eThe extreme cytotoxicity of natural enediyne antibiotics is attributed to the ability of the (Z)-3-ene-1,5-diyne fragment incorporated into a 10- or 9-membered ring cyclic system to undergo Bergman cyclization and producing dDNA-damaging p-benzyne diradical. The rate of this reaction strongly depends on the ring size. Thus 11-membered ring enediynes are stable, 10-membered ring analogs undergo slow cycloaromatization under ambient conditions or mild heating. Very little is known about reactivity of 9-membered ring enediynes due to their instability. We have developed thermally stable photo-precursors of 9-membered enediynes, in which one of the triple bonds is replaced by the cyclopropenone group. UV irradiation of the photo-precursor results in the efficient decarbonylation and the formation of reactive enediyne. The latter undergoes clean cycloaromatization spontaneously with absence of any chemical additives. Synthetic strategies of a series of cyclopropenone containing nine-membered enediyne precursors and DNA-cleavaging activity of the photo-generated enediynes have been also discussed.\u003c\/p\u003e\u003cdiv class=\"aw-variant-hidden-subtitle-div\" id=\"aw-variant-subtitle-9783844322873\"\u003e\u003ch3\u003eCYCLOPROPENONE-CONTAINING CYCLIC ENEDIYNE AND ENYNE-ALLENE PRECURSORS AS PROTOTYPE PHOTOSWITCHABLE ANTITUMOR AGENTS\u003c\/h3\u003e\u003c\/div\u003e","brand":"Autorenwelt Shop","offers":[{"title":"Softcover - 9783844322873","offer_id":39495974322269,"sku":"9783844322873","price":59.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0940\/0622\/files\/39e9c032-b031-486c-9a6c-4e32bfa78d3d.jpg?v=1770529898","url":"https:\/\/shop.autorenwelt.de\/products\/photoswitchable-nine-membered-cyclic-enediynes-and-enyne-allenes-von-dinesh-pandithavidana","provider":"Autorenwelt Shop","version":"1.0","type":"link"}