作者:Janne Möbius、Paul Margaretha
DOI:10.1002/hlca.200890240
日期:2008.12
The newly synthesized 2-(alk-3-en-1-ynyl)cyclohex-2-enones 4 undergo photodimerization (chemo- and regio-)selectively at the exocyclic CC bond to give diastereoisomeric mixtures of 1,2-dialkynyl-1,2-dimethylcyclobutanes. On irradiation of 4 in the presence of 2-chloroacrylonitrile, cyclobutane formation occurs again (chemo- and regio-)selectively at the exocyclic CC bond to afford diastereoisomeric
新合成的2-(alk-3-en-1-ynyl)cyclohex-2-enones 4在环外CC键处选择性进行光二聚化(化学和区域),得到1,2-二炔基-1的非对映异构体混合物, 2-二甲基环丁烷。在2-氯丙烯腈存在下辐射4时,在环外CC键上选择性地再次发生环丁烷形成(化学和区域),得到2-炔基-1-氯-2-甲基环丁烷腈的非对映异构体混合物。类似地,化合物4仅在环外CC键处进行光加成至2,3-二甲基丁-1,3-二烯,以提供[2 + 2]和[4 + 2]环加合物的混合物。