Initial screening of reactions conditions in the presence of a stoichiometric amount of DDQ^a.

Entry	Method	Acid	Solvent	Temp (°C)	Yieldb (%)
1	A		CH3CN	25	NRe
2	A		DCE	25	7
3c	A		DCE	25	11
4	A		DCE	80	18
5	B	TFA	DCE	25	10
6	B	TFA	DCE	80	28
7	B	MSA	DCE	80	59
8d	B	CBSA	DCE	80	58

^aReaction conditions: (Method A) (i) 6a (0.15 mmol), DDQ (0.22 mmol), MS 4 Å (20 mg), solvent (0.1 M), rt, 0.5 h; (ii) allyltributyl stannane (0.22 mmol), 24 h. (Method B) (i) 6a (0.37 mmol), DDQ (0.37 mmol), H₂O (0.41 mmol), DCE (0.1 M), rt, 24 h; (ii) allyltributyl stannane (0.75 mmol), LiClO₄ (0.37 mmol), acid (0.075 mmol), 24 h.

^bIsolated yield.

^cLiClO₄ (0.5 equiv.) was added.

^dThe reaction mixture was stirred for 6 h before allylstannane was added.

^eNo reaction.