Tris-[2.21]- and tris-[2.2.2]-σ-homobenzenes

✍ Scribed by Gabrielle McMullen; Gottfried Sedelmeier; Rainer Hildebrand; Hans Fritz; Horst Prinzbach

• Book ID: 104246537
• Publisher: Elsevier Science
• Year: 1979
• Tongue: French
• Weight: 187 KB
• Volume: 20
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)95540-6

✦ Synopsis

Tris-[2.2.1]-and tris-[2.2.2] -o-homobenzenes are synthesised by reaction of l,l'-bicyclobutenyl with appropriate dienophiles and hydrogenation of the adducts. 'X' 1 1 2 should be attained by means of the [2.2.1]-and [2.2.2]-homoand 12-membered transition states resp. In view of the conthe area of cyclobutabensenes 2,3) involving very similar synreport here our preliminary results, in so far as they are based on the l,l'-bicyclobutenyl described by Heinrich and Liittke 495) . Although 4 in TBF/pentane solution (2h, sealed tube, 60°C) failed to react with cyclopropene to give 5, it readily cycloadds 3-cyanocyclopropene 6) ) according to TLC and lH-NMR spectroscopy the addition takes place stereospecifically. 5b is isolat-ed as colourless prisms (m.p. '71.5-73'C, m/e = 171 (M+)) in a not yet optimised yield of 65% and is termined from assigned the cis-geometry from (J6 5+J6 9 -, ,) -(J S,S+JS,5) 2 5 llz (de- a high field 1 H-NW spectrum in [d6]-benzene) 8) and from the inter-