(Chief Bee)
08-16-03 03:21
No 453822
(Rated as: good idea!)
PCC Oxidation of Organoboranes Obtained Using Acetoxyborohydride
R.S. Dhillon, A.P. Kaur & G. Kaur
J. Ind. Chem. Soc. 77, 453-454 (2000) (../rhodium/pdf /safrole-mdp3
Summary
Alkenes are hydroborated using sodium triacetoxyborohydride1. The resulting organoborane is oxidized2 with PCC3, to form the corresponding aldehyde or ketone in 80% yield.
In Example #3, safrole subjected to the above one-pot reaction gives 3-(3,4-Methylenedioxyphenyl)-propionalde
My question is: What if isosafrole was used as the starting material instead of the safrole? In what proportions would the resulting ketones (MDP2P and MDP1P4) form? Will one of them form in a significantly higher amount than the other? This procedure could very likely become an excellent method of preparation of one of those ketones. Someone will just have to test the reaction and report back their analysis of their reaction product(s).
Notes:
[1] In the paper it is prepared from NaBH4/Hg(OAc)2/THF, but I strongly reccommend this instead: Post 439071 (Barium: "Prep of Sodium Triacetoxyborohydride", Novel Discourse)
[2] PCC is not absolutely required for this oxidation, as I have seen CrO3, as well as some peroxy-oxidant (H2O2 or Oxone) being used for the oxidation of organoboranes to ketones before. References upon request if you intend to try the reaction.
[3] Pyridine Chlorochromate
[4] MDP2P = 1-(3,4-Methylenedioxyphenyl)-2-propanone
(Active Asperger Archivist)
08-16-03 03:29
No 453825
both can be used directly in the synthesis of boron compounds as you describe for reactants in the above reaction. It's a US patent I saw a while back-
Post 204255 (obituary: "P2P", Novel Discourse)
That post has the basic idea in using boron compounds in other ways for ketone synthesis.
Bwiti, You should know which patent I'm talking about- we discussed it a long time ago. If you've got it, please post it.
(I'll search for it myself, but I can't guarantee anything.)
Act quickly or not at all.
(Chief Bee)
08-16-03 04:08
No 453832
I fetched all the articles mentioned in that thread. Good reading for everybody: Post 453831 (Rhodium: "Synthesis of ketones (P2P) via alkylboranes", Novel Discourse)
(Stranger)
09-13-03 11:27
No 458842
Isnt this somthiung to do with the rule, "the rich get richer" Markonvf's rule? (i can never remember the funny names) something to do with the addition of the oxygen at the site of the double bond. the oxygen atom will go to the side of the double bond that has the carbon with the most number of hydrogens attached or something along those lines... so im saying that the second (bottem) molucle with the oxygen on the observed right of the now broken dbl bond, will be the major product formed. this is just an opinion/geuss/ramble.
i dont know what to write hear so ill just leave it blank.