From: Paul Handley (p.handley$##$chemistry.uq.edu.au)
Date: Thu Mar 02 2000 - 23:34:58 EST
>Dear Friends:
>I need a simple procedure for the regio-selective allylic oxydationof
>Limonene (at the acyclic end). I am aware of Crawfords work (JACS, 1972,
>4298). HOwever, I am always getting about10% impurity, which is difficult
>to be seperated. I need pure alcohol.
>Since we cannot purchace n-BuLi used in this procedure, I normally make
>and titrate it against, a standard (say, diphenyl acetic acid).
>I would like to know, any other, cleaner and high yielding method for this
>oxydation.
>Krish M. Chary
>**************************************************************************
>Research Scholar
>School of chemistry Telephone: 3010500 extn:4807
>University Of Hyderabad
>Hyderabad- 500 046
>India
>
>e-mail: dbscrs$##$uohyd.ernet.in
I just found another procedure which you will definately want to check out,
High-yield method of preparing limonen-10-ol and menth-1-en-9-ol from
limonene. Chastain, Doyle E.; Mody, Naresh; Majetich, George. (USA).
U.S. (1996), 8 pp. CODEN: USXXAM US 5574195 A 19961112 Patent
written in English. Application: US 95-492372 19950619. CAN 126:8327
AN 1996:702071 CAPLUS
they use the same deprotonation with BuLi:TMEDA but quench the anion with
trimethyl borate/H2O2. Apparently the deprotonation step works much better
in petroleum ether than in hexane (my BuLi comes in hexane solution) and
longer reaction times than those reported by Crawford should be used.
Yield reported is 65-75%, remainder limonene.
Paul Handley
Dept. of Chemistry
University of Queensland
Brisbane, Australia
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