2,3-Dimethylene-2,3-Dihydrothiophene: The thiophene analogue of ortho-xylylene

✍ Scribed by Derek J. Chadwick; Andrew Plant

• Publisher: Elsevier Science
• Year: 1987
• Tongue: French
• Weight: 151 KB
• Volume: 28
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)96870-9

✦ Synopsis

The hitherto unknown 2,3-dimethylene-2,3_dihydrothiophene (the thiophene analogue of ortho-xylylene) and a substituted derivative have been prepared in solution and trapped as Diels-Alder adducts in good to excellent yields. ortho-Xylylene l_ has found wide application in organic chemistry, notably in the synthesis of natural products including steroids,1alkaloids,2 and anthracyclinones. 3We have now developed routes to the hitherto unreporteds thiophene analogue of o-xylylene 2_ (and to a substituted congener) based upon a directed metallation strategy for the construction of appropriate precursor molecules.