Photoaddition of dimethyl acetylenedicarboxylate to cyclic ethers

✍ Scribed by Prithipal Singh

• Book ID: 104249018
• Publisher: Elsevier Science
• Year: 1970
• Tongue: French
• Weight: 99 KB
• Volume: 11
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)98179-1

✦ Synopsis

The free radical addition of both aliphatic and alicyclic ethers to a variety of unsaturated substrates has been a subject of recent interest 192 . Jacobs and Ecke 3 reported the efficient addition of tetrahydrofuran (TEF) and tetrahydro-2-methylfuran to maleic anhydride but failed to observe any reaction with dimethyl acetylenedicarboxylate (DMAD). Our reinvestigation however showed that a 1:l photoadduct is indeed formed and the findings are reported below. DMAD in excess THF was irradiated under nitrogen with a 250-W Hanovia lamp through a Pyrex filter. After 20 hours the unchanged reactants were distilled under reduced pressure, and the residue was chromatographed on silica gel to giwz (I) as a colourless liquid4. The structure (I) is based on spectroscopic data: m/e 214 (parent ion); 'h,,,(neat) 5.81, 6.04, 9.30, 9.95 v: a(CC14) 1.7-2.3(m,4H), 3.68 and 3.73 (singlets, 6H), 5.12 (broad t, J=7 Hz, lH), and 6.42 (s,lIi). I C=CHCoocI13 V dOOCH3 Hydrolysis of (I) afforded a diacid (11)5, m-p. 112-i14O, hmax(EtOH) (log E) 206 (3.96), which on hydrogenation gave (III), m-p. 142-144O. The structure of (III) was established as tetrahydrofurylsuccinic acid by spectroscopic andmixed