ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 38, Number 11
JKCSEZ 38(11)
October 20, 1994 

8-Quinolinecarboxaldehyde (1) reacted with 1,5-hexadiene (2) in THF under Wilkinson's catalyst(3) and AgBF4 (8) to give a mixture of 8-quinolinyl 5-hexenyl ketone (4) and 8-quinolinyl 5-hexen-2-yl ketone (9) at initial reaction stage. The reason for the formation of the branched alkenyl ketone 9 is supposed to be that the vacant coordination site, generated from Wilkinson's catalyst and AgBF4, makes it possible to form the 5.5 membered ring metallacycle intermediate. The higher the concentration of AgBF4 was used, the greater the ratio of 9 to 4 was observed. Longer reaction time and high temperature induced isomerization of 9 and 4 to 10 and 5. Especially the high reaction temperature increased the possibility of cyclization of the 5-hexenyl metal intermediate to give 8-quinolinyl cyclopentylmethyl ketone (11).