Table 4.

Effects of various aldehyde substrates on the vinylogous Wittig transformation^a

Entry	Ar	Product	Yieldb [%]	E/Z ratioc
1	4-NCC6H4	4a	63	5:2
2	3-NCC6H4	4b	65	5:2
3	2-NCC6H4	4c	60	5:1
4	4-O2NC6H4	4d	51	4:1
5	3-O2NC6H4	4e	57	2:1
6	2-O2NC6H4	4f	50	7:2
7	3-FC6H4	4g	49	5:2

^aAllenic ester in CH₃CN (5 mL) was added in one portion to the mixture of the other components in CH₃CN (10 mL).

^bIsolated yield.

^cRelating to the geometry around the newly formed double bond; the ratio was determined after integration of the signals of protons H^a and H^b in the ¹H NMR spectrum of the crude reaction product.