Table 1. Effect of Reaction Parameters on the Cyclization of Styrene Oxide with Styrene^a.

entry	deviation from the “standard condition”	C (Y) (%)b	d.r.c
1	none	quant (98)	78:22
2	4 h instead of 16 h	quant (98)	78:22
3	3 mol % 11 instead of 5 mol % 11, 6 h	quant (98)	78:22
4	2 mol % 11 instead of 5 mol % 11	95 (85)	78:22
5	1 mol % 11 instead of 5 mol % 11	90 (75)	78:22
6	12 instead of 11	NCd
7	13 instead of 11	NC
8	14 instead of 11	NC
9	16 instead of 11	42 (40)	69:31
10	18 instead of 11	36 (33)	60:40
11	20 instead of 11	35 (33)	67:33
12	21·FeCl2 instead of 11	19 (18)	70:30
13	22 (20 mol %) instead of 11 (5 mol %)	NDe (79)	70:30
14	Mn instead of Zn	NC

^aReactions were carried out under nitrogen atmosphere using 1.0 mmol racemic styrene oxide ((±)-1a).

^bC: Conversion, determined by GC analysis using diphenyl ether as internal standard. Y: Isolated yield.

^cd.r.: Diastereomeric ratio, determined by ¹H NMR spectroscopy.

^dNC: No conversion.

^eND: Not determined.