[studytogether]

there are two kinds of reactions related to mutiple bond?

sometimes the reaction related to mutiple bond is result from electrons in bond attack other compounds?

sometimes the reaction related to multiple bond is result from attack of multiple bond by other compounds?

why?

[trufalup]

there are two kinds of reactions related to mutiple bond?


[Yup, perhaps 3 then?. pericyclic/cylco-addition]


sometimes the reaction related to mutiple bond is result from electrons in bond attack other compounds?


[extra electron density (TT orbital in this case) always could be nucleophilic, you just have to find the right electrophile to match, ie. H+ not a carbonyl in this case--- HASB theory ]


sometimes the reaction related to multiple bond is result from attack of multiple bond by other compounds?


[P, N, S, nucleophiles take advantage of a low lying TT* orbital that alkenes possess]


why?

[Kryolith]

I'm not sure about your question, however I'll try to answer:

Alkenes/alkynes can react with various compounds. They can react with themselves, too. This
type of reactions are called pericyclic reactions. (Of course a pericyclic reaction can occur not only between alkenes/alkynes). Although every pericyclic reaction can be considered as a cycloaddition there are formally 5 types:

cycloaddition, electrocyclic, sigmatropic, cheletropic and group-transfer reactions.

EDIT:
of course carbonyl/nitrile groups etc. are multiple bonds, too. There are many reactions concerning that kind of functional groups.

[sjh9]

there are two kinds of reactions related to mutiple bond?

sometimes the reaction related to mutiple bond is result from electrons in bond attack other compounds?

sometimes the reaction related to multiple bond is result from attack of multiple bond by other compounds?

why?

Here is a book that may help you:

http://www.amazon.com/Frontier-Orbitals-Organic-Chemical-Reactions/dp/0471018198/ref=sr_1_1?ie=UTF8&s=books&qid=1200548636&sr=1-1

[AWK]

http://www.cem.msu.edu/~reusch/VirtualText/addene2.htm