Preparative UV-VIS laser photochemistry: Photocycloadditions of methylenelactones with benzophenone andp-benzoquinone. Oxygen trapping of paterno-Büchi triplet 1,4-diradicals as model reactions for quinghaosu-type 1,2,4-trioxanes

✍ Scribed by Adam, Waldemar ;Kliem, Ulrike ;Lucchini, Vittorio

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 783 KB
• Volume: 1988
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.198819880909

✦ Synopsis

Thc UV-VIS laser irradiatiun o f 4-puntcn-4-olidc ( I ) with hcii-Lophenone (BPI o r with p-bcnzoquinone (BQ) undcr an argon xtniosphcrc dTorded the acctal-type oxctanes 2-BP arid 2-BQ. rcspcctivrly. Only for BP was the oxctanc regioisorncr 3-BP oht;iinrd. x t u a l l y iis rn;ijnr product. while 3430 appears to be photolabilc iiiidcr VIS-lriscr phoiolysis conditions and thus docs no! xcuniulaic i n sullicicnt iirnounis Tor dctcction. Under iin nxygcn ainiosphsrc. hcsidcs thcsc oxctane products ;11so the 1 ,?.4-trioxm c s 5-PR ;mi 5-BQ, rhc oxygen trapping products r d thr: intcr-After 4.3 h irradiation (455-515 nm) of a solution of diketene and BQ in C C 4 (argon atmosphere), the starting Liebigs Ann. Chem. 1988, 869-875 ') D. L. Klayman, Science 228 (1985) 1049.