title: Thermal [2+2] cycloaddition of allenynes: easy construction of bicyclo[6.2.0]deca-1,8-dienes, bicyclo[5.2.0]nona-1,7-dienes, and bicyclo[4.2.0]octa-1,6-dienes.
abstract: The simple refluxing of allenynes, having a phenylsulfonyl functionality on the allenyl group, in xylene (or mesitylene) without microwave irradiation resulted in the efficient formation of bicyclo[5.2.0]nona-1,7-dienes and bicyclo[4.2.0]octa-1,6-dienes in high yields. This method was shown to be successfully applicable to the first construction of bicyclo[6.2.0]deca-1,8-dienes. Construction of the corresponding oxa- and azabicyclo[m.2.0] frameworks could also be attained. This thermal ring-closing reaction involves the formal [2+2] cycloaddition in which the distal double bond of an allenyl moiety exclusively served as one of the pi-components regardless of the position of the phenysulfonyl functionality on the allenyl moiety.
authors.affiliation: Division of Pharmaceutical Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. cmukai@kenroku.kanazawa-u.ac.jp
authors.forename: Chisato
authors.initials: C
authors.lastname: Mukai
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Hara
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Miyashita
authors.forename: Fuyuhiko
authors.initials: F
authors.lastname: Inagaki
mesh_terms: D000466:Alkadienes / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis*; D003500:Cyclization; D003516:Cycloparaffins / Q000138:chemical synthesis*
chemical_list: D000466:Alkadienes; D000480:Alkynes; D019086:Bridged Bicyclo Compounds, Heterocyclic; D003516:Cycloparaffins; C025947:propadiene