Question

question 9 (1 point)
use the following information to answer the next question.
consider the following addition reaction:
ch3 - ch2 - c ° c - ch3 + 2h2xrightarrow90^{circ}c{ni} ch3 - ch2 - ch2 - ch2 - ch3
the iupac name of the first reactant is
a) pent - 3 - ene
b) pent - 3 - yne
c) pent - 2 - ane
d) pent - 2 - ene
e) pent - 2 - yne

Explanation:

• First, identify the functional group. The reactant has a triple bond ($-C\equiv C-$), so it is an alkyne (ending with -yne).
• Then, count the number of carbon atoms. There are 5 carbon atoms (prefix pent -).
• Next, number the carbon chain. For alkynes, we number to give the triple - bond the lowest possible number. In $CH_{3}-CH_{2}-C\equiv C - CH_{3}$, the triple bond is between carbon 2 and 3. But when we number from the end that gives the triple bond the lower number, we start from the right - hand side (because $2<3$ when numbering from the right, the triple bond is at carbon 2).

Answer:

e) pent - 2 - yne