Table 2. Optimization of Glycosylation Conditions^a.

entry	base	sulfonylating agent	yield (%)b	β/α ratioc
1	KN(SiMe3)2	4i	46	β only
2	LiN(SiMe3)2	4i	NR	NR
3	NaN(SiMe3)2	4i	69	β only
4d	NaN(SiMe3)2	4i	81	β only
5d,e	NaN(SiMe3)2	4i	96	β only
6d,e	NaN(SiMe3)2	4h	85	β only

^a0.20 mmol of glucosyl donor 1, 0.13 mmol of acceptor 2, 0.20 mmol of TTBP, 0.20 mmol of sulfonylating agent, THF as the solvent, 2 h of activation time. Glycosylation was run at −15 °C. Glycosylation [1] = 0.050 M.

^bIsolated yield.

^cAll selectivities based on ¹H NMR analysis of purified material (see SI).

^dWithout adding TTBP.

^e0.20 mmol of 1, 0.1 mmol of acceptor 2, glycosylation [1] = 0.059 M. Glycosylation was run at −30 °C. TTBP = 2,4,6-tri-tert-butylpyrimidine. NR = no reaction.