Table 1.

Cyclopropanation methods for the preparation of esters 3a–k

entry	compound	Ar	% yielda, (method A)4	% yielda, (method B)5
1	3a	4-CF3C6H4	27	96
2	3b	4-BrC6H4	50	94
3	3c	4-CH3OC6H4	50	98
4	3d	4-NO2C6H4	5	65
5	3e	2-thienyl	40	97
6	3f	3-thienyl	59	99
7	3g	2-furyl	27	94
8	3h	3-furyl	21	99
9b	3i	3-pyridyl	34	-
10b	3j	1-napthyl	65	-
11c	3k	N(Ts)-5-indoyl	-	97

^aYields are for isolated product using 1.4 – 1.8 mmol of alkene substrate.

^bCyclopropanation by Method B gave inseparable and/or complex mixtures.

^cCyclopropanation by Method A not attempted on this substrate.