McMurry (Kap. 17,2)

Question 1

How is alkenes named?

Answer 1

set of rules (similar to naming alkanes).

1) Name the parent hydrocarbon (find the longest carbon chain containing the double bond) - use the suffix ene in place of -ane.

2) Number the carbon atoms in the chain so the double bond gets the less number. If both the same from each side, let the substituent get the less number.

3) List the substituents alphabetically (if more then one), Indicate the position of the double bond by placing the number directly before the -ene suffix. (if more then one double bond present - diene, triene etc…).
2-methylhex-3-ene

se page 183 for tutorial and examples.

Question 2

How is cycloalkenes named?

Answer 2

The double bond is always between C1 and C2. And the first substituent has as low number as possible.

see page 184 for examples.

Question 3

Some alkenes have common names that dont follow the IUPAC and that you have to memorise (see table 7,1 - page 184).

Answer 3

see page 184

Question 4

How are alkynes named? (C-C triple bond)

Answer 4

Just like alkenes, but with the suffix -yne insted of -ene.

Numbering should have the triple bond the lowest number.

Componds with more than one triple bond = diynes, triynes etc..

Question 5

compounds that contain both triple bonds and single bonds, what are they called?

Answer 5

enynes.

numbering starts from the first multiple bond (whether double or triple bond if there is a substituent so it gets the smaller number), or that the two bonds are smaller numbers together, but if there is no substituent, the double bond gets the smaller number.

Question 6

As with alkyl groups from alkanes (methyl, ethyl, propyl)

alkenyl (alkenes) and alkynyl (alkynes) are also possible:

• butyl (alkyl)
• Nut-1-enyl (a vinylic group, alkene)
• But-1-ynyl (an alkynyl group, an alkyne).

See page 184 for (methylene group, a vinyl group, and a allyl group for the alkene (like alkyl) substituents):

Answer 6

see page 185 and 184