June 20, 2024, 02:41:48 AM
Forum Rules: Read This Before Posting


Topic: Alkene reactivity  (Read 2697 times)

0 Members and 1 Guest are viewing this topic.

Offline luscofusco

  • Regular Member
  • ***
  • Posts: 12
  • Mole Snacks: +0/-0
Alkene reactivity
« on: February 17, 2023, 05:36:53 AM »
I'm doing this exercise and it says provide reaction conditions. My idea is:

1. I can get OH on carbon 2 by a hydroboration oxidation
2. I can get OH on carbon 1 by oximercuriation demercuriation.

My question is: can I do both? If I do one I need an elimination to get the alkene again (this is just a guess, I'm not 100% sure) but isn't the H from the OH going to react faster than any of the other ones?

Since both OH are on the same plane, does epoxidation (for example with MCPBA) even work here? Because it would flip the configuration due to backside attack.


Offline Hunter2

  • Sr. Member
  • *****
  • Posts: 2215
  • Mole Snacks: +178/-48
  • Gender: Male
  • Vena Lausa moris pax drux bis totis

Offline rolnor

  • Chemist
  • Sr. Member
  • *
  • Posts: 2241
  • Mole Snacks: +151/-10

Offline Enthalpy

  • Chemist
  • Sr. Member
  • *
  • Posts: 4038
  • Mole Snacks: +304/-59
Re: Alkene reactivity
« Reply #3 on: February 21, 2023, 06:17:33 PM »
For my information: how toxic is OsO4? I read astonishing data.

Offline Hunter2

  • Sr. Member
  • *****
  • Posts: 2215
  • Mole Snacks: +178/-48
  • Gender: Male
  • Vena Lausa moris pax drux bis totis
Re: Alkene reactivity
« Reply #4 on: February 22, 2023, 05:43:31 AM »
There are a lot of toxic compounds, lice arsenic, cyanide, phosgen, a.o. If to work with it , the corresponding safety rule and features  have to be used

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3653
  • Mole Snacks: +222/-42
  • Gender: Male
Re: Alkene reactivity
« Reply #5 on: February 24, 2023, 07:25:33 AM »
Its a chiral product so you need to do asymetric dihydroxylation.

https://en.wikipedia.org/wiki/Sharpless_asymmetric_dihydroxylation

True - but it might just be referring to the Z diastereomeric pair.


Offline rolnor

  • Chemist
  • Sr. Member
  • *
  • Posts: 2241
  • Mole Snacks: +151/-10
Re: Alkene reactivity
« Reply #6 on: February 24, 2023, 03:16:23 PM »
As the structure of the compound is drawn, its chiral. It can be non-correctly drawn, yes. I think OsO4 will hydroxylate double-bonds in the body and be re-oxidized so even small amounts will hurt the biology inj the body. Compounds like phosghene will be consumed and will be neutralized in the body, its not catalytical. Many toxic things in nature are enzymes, Botuline and many snake-venoms are enzymes and they catalyticaly interfere with the biochemistry. I have worked a lot with OsO4 and its volatile, you get it in the rotavapor solvent waste, you get it everywhere. Not very nice.

Offline Babcock_Hall

  • Chemist
  • Sr. Member
  • *
  • Posts: 5640
  • Mole Snacks: +325/-24
Re: Alkene reactivity
« Reply #7 on: February 27, 2023, 01:31:39 PM »
There is a method that uses NMO (the N-oxidized form of N-methylmorpholine) as the oxidant, with OsO4 as the catalyst.  My inference is that using NMO is a safer alternative to using stoichiometric OsO4.

Offline rolnor

  • Chemist
  • Sr. Member
  • *
  • Posts: 2241
  • Mole Snacks: +151/-10
Re: Alkene reactivity
« Reply #8 on: March 13, 2023, 02:09:24 PM »
OsO4 is expensive and toxic so deffinetly use it catalytic.

Sponsored Links