Table 2.

Addition reaction using other N,O-acetals 1 and alkynes 3.

entry	R1	compound	R2	compound	product	yield, %
1	p-MeC6H4	1a	Bu	3b	4b	58
2	p-MeC6H4	1a	t-Bu	3c	4c	55
3	p-MeC6H4	1a	Me3Si	3d	4d	69
4	Et	1b	Ph	3a	4e	72