# What will be the major product when conjugated alkene (like 1,3-butadiene) is reacted with HBr in presence of R2O2?

What will be the major product when conjugated alkene (like 1,3-butadiene) is reacted with $$\ce{HBr}$$ in the presence of $$\ce{R2O2}$$?

As we know, two products are formed when no $$\ce{R2O2}$$ is used because of conjugation in double bond and carbocation. But when $$\ce{R2O2}$$ is used, free radical is formed.

So, will there be the same case in the following question as well? Also, if answer is yes, then what will be the major product?

• Please convert the image into a better form.. You can use this to do so. Jul 16 '20 at 14:47
• The 6-member ring is highly suggestive...
– Zhe
Jul 16 '20 at 15:14