Table 2. Reaction of Glycals 1b–1f, 4a, 4b and 5 with Model Glycoside Acceptor 2a.

entry		R1	R2	R3	product (time (h))	yield (%)a	α:βb
1	1b	Bn	Bn	Ac	6b (0.7)	94	>30:1
2	1c	Bn	Bn	TIPS	6c (3)	65	6:1
3	1d	MOM	MOM	MOM	6d (6)	76	>30:1
4	1e	TBS	TBS	TBS	6e (2)	78	>30:1
5	1f	Ac	Ac	Ac	6f (−)	–	N/A
6	4a	O[Si(i-Pr)2]2		Bn	7a (3)	78	>30:1
7	4b	O[Si(i-Pr)2]2		TIPS	7b (2)	83	>30:1
8	5	O[Si(i-Pr)2]2		–	8 (1)	91	5:1

^aIsolated yield.

^bDetermined by ¹H NMR. N/A = not applicable.