Table 1. Optimization studies for the divergent cyclopropanation ^{a , b} .

Entry	Base	Solvent	3a (%)	4a (%)
1	NaH	CH3CN	13	—
2	NaH	1,2-DCE	33	—
3	NaH	DMSO	19	34
4	NaH	DMF	—	82 c (81 d )
5	NaOMe	DMF	51	—
6 e	NaOMe	DMF	86 (83 d )	—
7	KOtBu	DMF	26	29

^aConditions: 1a (0.1 mmol), 2a (2 equiv.), base (2 equiv.), solvent (1 mL), 25 °C, 18 h.

^bNMR yield using CH₂Br₂ as an internal standard.

^c2.5 mL of solvent was used.

^dIsolated yield.

^e2.5 equiv. of 2a and NaH were added to 2.0 mL of solvent at 40 °C.