Destroyer Organic #183

[2012hopefull]

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Prob a stupid question. Why is the answer A and not E? I know its anti Mark so I am thinking the OH should go to the less sub side. thanks for your help.

 

[jefff]

no question is stupid.
this is hydroboration (can see it written with diborane B2H6 or borane BH3)

you're right to say/think right away it is anti-markovnikov

then think where is this double bond you are going to add a hydroxyl to

then you will clearly see the answer

the carbon on the ring is secondary, while the CH2 is primary

therefore anti-markovnikov addition of an -OH to the least substituted carbon on the double bond

*note a -H is added to the more substituted carbon on the double bond, and is added in a syn fashion (attacked from the side side/angle the -OH attacked the least substituted carbon)

this may help in regards to showing the syn addition across the double bond

good luck!

Prob a stupid question. Why is the answer A and not E? I know its anti Mark so I am thinking the OH should go to the less sub side. thanks for your help.

 

[2012hopefull]

Thank you so much. I dont know why I could not see that before 🙂