Table 1.

Substrate Scope of α-Quaternary Cyclic Hydroxamic Acid Derivatives^a

entry	substrate	R	yield (%)b	ee (%)c
1		Bz (3a→4a)d	98	73
2		Boc (3b→4b)	95	72
3		PhO(CO) (3c→4c)	95	73
4		Bz (3d→4d)	29	88
5		Piv (3e→4e)	48	73
6		Bn (3f→4f)	trace	ND
7		Boc (3g→4g)	67	85
8		Cbz (3h→4h)	89	84
9		PhO(CO) (3i→4i)	70	87
10			81	93

^aReaction performed under the conditions of Figure 3 at 60 °C.

^bAll reported yields are for isolated products.

^cEnantiomeric excesses were determined by chiral SFC analysis.

^dAbsolute configuration was assigned by VCD spectroscopy22 supported by theoretical calculations (see supporting information).