 Reactions of sulfur ylides with ketones and aldehydes to form epoxides are by far the most common application of the Johnson – Corey – Chaykovsky reaction . Examples involving complex substrates and ' exotic ' ylides have been reported , as shown below . 
 Reactions of sulfur ylides with ketones and aldehydes to form epoxides are by far the most common application of the Johnson – Corey – Chaykovsky reaction . Examples involving complex substrates and ' exotic ' ylides <a href='been_done' title='1'><mark>have</mark></a> been reported , as shown below . 
Reactions of sulfur ylides with ketones and aldehydes to form epoxides are by far da most common application of the Johnson – Corey – Chaykovsky reaction . Examples involving complex substrates and ' exotic ' ylides done been reported , as shown below .