Table 1. Effect of the Reaction Conditions on the Formation of Rearranged Products 2a and 3a.

entrya	base	amount of base (eq)	solvent	2a:3a ratiob	yield (%)
1	t-BuOK	1	THF	1:0	83 (2a)
2	t-BuOK	2	THF	1:0	90 (2a)
3	t-BuOK	3	THF	1.00:0.88	87 (2a+3a)
4	t-BuOK	4	THF	0.31:1.00	80 (2a+3a)
5	t-BuOK	6	THF	0.09:1.00	84 (2a+3a)
6	t-BuOK	8	THF	0.13:1.00	88 (2a+3a)
7	t-BuONa	6	THF	0.09:1.00	85 (2a+3a)
8	KOH	6	THF	1:0	89 (2a)
9	NaOMe	6	THF	1:0	76 (2a)
10	NaNH2	6	THF	1:0	74 (2a)
11	t-BuOK	6	2-Me-THF	0.14:1.00	88 (2a+3a)
12	t-BuOK	6	1,4-dioxane	0.10:1.00	87 (2a+3a)
13	t-BuOK	6	DME	0.14:1.00	79 (2a+3a)
14	t-BuOK	6	DMFc	0.12:1.00	93 (2a+3a)
15	t-BuOK	6	DMSOd	0:1	84 (3a)
16	t-BuOK	6	t-BuOH	1:0	88 (2a)

^aReagents and reaction conditions: 1a (0.6 mmol), base, solvent (3 mL), 25 °C, 30 min, then quenching with H₂O, evaporation and crystallization.

^bThe product ratio of the isolated mixtures was determined by ¹H NMR.

^cH₂O was added after evaporation.

^dWithout evaporation.