Table 2.

syn-Diastereo- and enantioselective carbonyl crotylation from the aldehyde oxidation level.^a

Entry	Product	Ligand	Yield [%]	ee [%]	syn:anti
1		A	76	88	12:1
2		A	80	93	19:1
3		A	71	88	≥20:1
4		B	91	90	≥20:1
5		B	75b	93	11:1
6		A	56b,c	90	≥20:1
7		A	71b	91	≥20:1
8		A	66	84	≥20:1
9		A	53b,c,d,e	84	≥20:1
10		A	50b,d,e	84	≥20:1

^aLigand A = (R)-DM-SEGPHOS, Ligand B = (R)- SEGPHOS. Yields are of isolated material. Diastereoselectivity was determined through ¹H NMR analysis of crude reaction mixtures. Enantiomeric excess was determined by chiral stationary phase HPLC analysis. See Supporting Information for details.

^b250 mol% 1.

^cTHF

^d7 mol% catalyst.

^e72 hours.