Table 1. Optimization of Reaction Conditions in a Reaction of 5a and p-TolMgBr^a.

entry	5a/p-TolMgX (equiv)	temp (°C)	8a (%)b	9 (%)b
1	1:1.1	–78	36	29c
2	1:1.1	–25	71	17
3	1:1.1	rt	76	7
4	1:/1.1	0	65	10
5	1:1.8	0	83	10
6	1:2.5	0	83	0
7d	1:1.5	0	98	0

^aReaction conditions: 5a (0.13 mmol), ArMgBr (0.195 mmol), THF (2 mL).

^bIsolated yields.

^cStarting material 5a and 1-phenylbenzophospholan-3-one oxide (3a) were present in the crude reaction mixture.

^dReaction was carried out for 30 min.