The cyclopropanation by using chiral ylide 3d with methacrylate has been studied as a model for this reaction. We screened different solvents and found that the acetonitrile at room temperature is ideal one and gives good chemical yield and diastereoselectivity (Fig. ). where characterized as 1R,2S by ORTEP where the methyl ester group is cis to chiral amide. The acrylaldehyde also 3 products 21a, 21b and 21c after repeated recrystallizations, no crystals were formed, whereas the acrylonitrile gives full spectrum of four possible products 22a, 22b, 22c and 22d. The vinyl methyl ketone gives mixture of products 23 which are inseparable. These multiple products formations can be explained that chiral ylide can be attack from either side of simple -unsaturated carbonyl substrates. As expected, fumarate gives 9b, (1S, 2R) as major product, but surprisingly, the maleate also gives same 9b (1R, 2S) as major product. This can be explained the esters groups are in cis orientation is most stable than anti orientation. Surprisingly, the hexenaldehyde is gives more selective product 24b with chiral ylide. To improve the selectivity, we generated in situ chiral sulfide from chiral diazo in presence of Rh2(OAc)4