Optimizations of reaction conditions^a.

Entry	Variation from standard conditions	eeb (%)	Yieldc (%)
1	None	92	88
2	L2 instead of L1 as ligand	—	Trace
3	L3 instead of L1 as ligand	13	<5%
4	L4 instead of L1 as ligand	—	Trace
5	L5 instead of L1 as ligand	−80	—
6	L6 instead of L1 as ligand	72	33
7	Et3N instead of DBU as base	89	33
8	DABCO instead of DBU as base	88	35
9	TBD instead of DBU as base	86	37
10	1,4-dioxane instead of THF as solvent	91	86
11	Toluene instead of THF as solvent	87	64
12	–OBz instead of –OCOOMe	93	38
13	–Cl instead of –OCOOMe	–3	46
14	–OPO(OEt)2 instead of –OCOOMe	50	42
15	–OBoc instead of –OCOOMe	89	34

^aReaction conditions: all reactions were run on 0.1 mmol scale with respect to 1.

^bee determined by chiral HPLC.

^cIsolated yield. DABCO = 1,4-diazabicyclo[2.2.2]octane, DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene, TBD = 1,5,7-triazabicyclo[4.4.0]dec-5-ene.