[Squeak1107]

I'm trying to figure out the reagents and conditions for some reaction of alkenes.

1) Cyclohexane --> trans-cyclohexan-1,2-diol
I know that to make the cis isomer you use OsO₄ but i have no idea how i would make the trans isomer.

2) the reaction from cyclopentene to pentan-1,5-diol.
For this reaction i'm really not sure where to start.

Any help would be much appreciated! Thanks

[sjb]

OsO₄ will not react directly with cycloalkanes to form diols -  what intermediates might you need?

What reactions of alkenes do you know, how can you form alcohols?

[Squeak1107]

OsO₄ will not react directly with cycloalkanes to form diols -  what intermediates might you need?

What reactions of alkenes do you know, how can you form alcohols?

For the first one i've said it would need NaSO₃ and H₂O or NMO and t-BUOH. From what i understand they act to oxidise the Os from Os(VI) to Os(VIII) and therefore catalyse the reaction.However from my understanding using OsO₄ is entirely stereospecific

To form alcohols you could react with steam to hydrate them but i think that only gives you one OH group.

Thank you for helping me out!

[kriggy]

For trans diol you need different approach than OsO4 or KMnO4

[sjb]

For the first one i've said it would need NaSO₃ and H₂O or NMO and t-BUOH. From what i understand they act to oxidise the Os from Os(VI) to Os(VIII) and therefore catalyse the reaction.However from my understanding using OsO₄ is entirely stereospecific

To form alcohols you could react with steam to hydrate them but i think that only gives you one OH group.

Thank you for helping me out!

Na₂SO₃ will re-oxidise the Os(VI) species, yes, but you still need a different intermediate.

How does the starting material for your second reaction differ from the one you have listed for your first? For part two it may not be a one step reaction.

[Babcock_Hall]

I would work these problems backwards.  Start with the product and ask what can be converted into it.  As others have noted, more than one step may be required.

[Dan]

I'm trying to figure out the reagents and conditions for some reaction of alkenes.

1) Cyclohexane --> trans-cyclohexan-1,2-diol
I know that to make the cis isomer you use OsO₄ but i have no idea how i would make the trans isomer.

Cyclohexane or cyclohexene? I think this may be causing some confusion.