[OldThrashbarg]

As I understand it, the Tebbe Reaction can replace a carbonyl group with a C=CH2 group and works with a wide variety of carbonyls (including esters and lactones).  The Takai Reaction instead replaces the carbonyl group with a C=CHX group, where X is a halogen.  However, my understanding is that the unmodified Takai reaction only works on aldehydes (and possibly some ketones).  Does anyone know of a successful use of the Takai reaction, or a modified version of either reaction to replace the carbonyl group in a lactone with C=CHX?

[AWK]

http://en.wikipedia.org/wiki/Tebbe's_reagent
http://www.princeton.edu/~orggroup/supergroup_pdf/jinglongchenPresentation-upload.pdf