Carbenes + Addition of Carbenes

Question 1

what is a carbene?

Answer 1

carbon with a lone pair and 2 R groups

very reactive

resembles a carbocation and a carbanion

Question 2

hybridization and val e-

Answer 2

sp2

6 val e-

Question 3

addition of carbene to alkene

Answer 3

concerted alkene Nu attack of carbene p orbital, and lone pair from carbene attacking an alkene carbon

stereochemistry of original alkene is preserved