Table 1.

Optimization of the Reaction Conditions^a

Entry	Catalyst	Solvent	Timeb (h)	Ratio 1a/2a	Yieldc (%) of 6a
1	3a	CH2Cl2	4.5	1:1	– d
2	3a	CHCl3	4.5	1:1	– d
3	3a	toluene	4.5	1:1	– d
4	3a	DMSO	4.5	1:1	10
5	3a	MeOH	4.5	1:1	51
6	3a	EtOH	4.5	1:1	50
7	3b	EtOH	4.5	1:1	10
8	3c	EtOH	4.5	1:1	–
9	3d	EtOH	4.5	1:1	–
10	3a	EtOH	3	1:1	42
11	3a	EtOH	8	1:1	46
12	3a	EtOH	16	1:1	– d
13	3a	EtOH	4.5	1:1.5	–
14	3a	EtOH	4.5	1.5:1	65
15	3a	EtOH	4.5	2:1	66

^aUnless otherwise noted, all reactions were performed on a 0.33-mmol scale using the indicated ratio of 1a/2a, catalyst (20 mol%), solvent (1.5 mL), r.t., for the indicated time, followed by addition of the Wittig reagent (1.5 equiv) with reaction overnight.

^bTime for the domino reaction before the introduction of the Wittig reagent.

^cIsolated yield.

^dA mixture of 7 and 8 was obtained.