The effect of catalyst, acylating reagent, base, and solvent.

Entrya	Catalyst	Acylating reagent	Solvent	Yieldb (%)	eec (%)
1	OAc-DPI	ClCOOBn	Toluene	77	84
2	OMe-DPI	ClCOOBn	Toluene	62	87
3	OEt-DPI	ClCOOBn	Toluene	65	88
4	OBn-DPI	ClCOOBn	Toluene	78	91
5	OBn-DPI	ClCOOallyl	Toluene	71	91
6	OBn-DPI	ClCOOPh	Toluene	81	60
7	OBn-DPI	ClCOOEt	Toluene	Trace	—
8d	OBn-DPI	ClCOOBn	Toluene	—	—
9	OBn-DPI	ClCOOBn	THF	80	90
10	OBn-DPI	ClCOOBn	Dioxane	77	90
11	OBn-DPI	ClCOOBn	Et2O	30	91
12	OBn-DPI	ClCOOBn	MTBE	66	91
13	OBn-DPI	ClCOOBn	DCM	45	88
14	OBn-DPI	ClCOOBn	t-AA	76	71

^aConditions: 1a (0.1 M), ClCOOR (3.5 eq.), catalyst (20 mol%), DIPEA (4.0 eq.), solvent (2 mL), 20 °C, 36 h, unless otherwise noted.

^bYields were calculated from ¹H NMR spectra.

^cThe ee values were calculated from HPLC spectra.

^dTEA was used instead of DIPEA and only azlactone without COOBn substituent was obtained together with some NEt₂COOBn.