Jordan Cummins (Princeton '99) and Tim Porter, (Princeton '87) generated this carbene in order to investigate a mechanism for cyclopropylcarbene reactions. We had suggested that mechanism nearly 30 years ago, but had become disenchanted with it over the years. Jordan and Tim's work strongly indicates that our old mechanism was right after all.

Here is what happens when the carbene is generated.

You can read all about it in J. Am. Chem. Soc. 1998, 120, 6473.