Table 1 Summary of key reaction parameter effects^a


Entry	Deviation from standard conditions	Yield (%)^b	e.e. (%)^c
1	None	97	97
2	(S)-4b	77	93
3	(S)-4c	56	81
4	(S)-4d	89	95
5	(S)-4e	37	20
6	(S)-4f	57	67
7	(S)-4g	62	66
8	without MgSO₄	53	97
9	Na₂SO₄ instead of MgSO₄	45	81
10	4 Å MS instead of MgSO₄	trace	ND
11	CHP instead of H₂O₂	16	93
12	TBHP instead of H₂O₂	27	97
13^d	CH₂Cl₂ instead of Toluene	96	97

^aStandard reaction conditions using 1aa (0.1 mmol), 2 (0.2 mmol), MgSO₄ (120 mg), and (S)−4a (3 mol %) at 35 ^oC for 5 h in toluene (1.0 mL) unless otherwise noted. ^bIsolated yields. ^cEnantiomeric excess (e.e.) and diastereomeric ratio (d.r.) values were determined using chiral HPLC analysis or ¹H NMR analysis (GC). ^d18 h. MS molecular sieves; CHP cumene hydroperoxide; TBHP tert-butyl hydroperoxide; ND not detected.

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