The addition of Grignard reagenta to a,,9 -unsaturated carbonyl compounds has been the subject of many investigations. Rohler et al. ( ) have reported that ethyl cinnamate gives exclusively the 1,2-addition product with methylmagnesium iodide, but predominantly the 1,4-adduct with phenylmagnesium bromide. It ie also known that chalcone reacted with phenylmagnesium bromide to give ai-addition product, accompanying with the 1,4-adduct. (3) In thie communication we wish to report the novel reaction of benzylideneacenaphthenones (I) with Grignard reagents. When Ia (R=H) was treated with phenylmagnesium bromide (IIa) in ethyl ether-benzene, white needles (IIIa), m.p. 184-185O, and yellow neelles (IVa), m.p. 103-104ยฐ, were obtained in yields of 31 and 29% respectively. The compound IIia was confirmed to be the expected 1,4-adduct., 2_benzhydrylacenaphthenone, on the basis of the following evidences. The compound IIIa was in agreement with the formula C,,H,,O and ita mass spectrum showed the parent peak at m/e 334. The IR spectrum exhibited the band at 1718 cm+ and NER spectrum in CDCl, showed peaks at x5.0, 4.6 (each lH, doublet, J=6 cps) and 2.5 (16H, multiplet).
On the other hand, the molecular formula of IVa did not agree with an l:ladduct, but it agreed with C e7H2z0. The mass spectrum of IVa ehowea the parent