Process for preparing stereospecific farnesylacetic acid and ester thereof
AssigneeKuraray Co., Ltd.
InventorsYoshiji Fujita, Yoshiaki Omura, Takashi Nishida, Kazuo Itoi
Life of this patent
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Abstract
A process for preparing stereospecific farnesylacetic acid and ester thereof by rectifying a mixture of .DELTA..sup.4,8 -trans- and .DELTA..sup.4 -cis-.DELTA..sup.8 -trans-farnesylacetic acids or esters thereof or .DELTA..sup.4,8 -trans- and .DELTA..sup.4 -cis-.DELTA..sup.8 -trans-farnesylacetic acid or esters thereof or a mixture of four isomers of the said farnesylacetic acids or esters thereof.
Claims15
A process for preparing a stereospecific farnesylacetic acid or ester thereof, at .DELTA..sup.4 and .DELTA..sup.8 positions, having the formula:
- ##STR20## wherein R.sub.2 represents hydrogen atom, a lower alkyl radical having 1 to 6 carbon atoms, a lower cycloalkyl radical having 3 to 6 carbon atoms, a lower alkenyl radical having 2 to 6 carbon atoms or a lower cycloalkenyl radical having 3 to 6 carbon atoms, which comprises rectifying a stereo isomeric mixture of farnesylacetic acids or esters thereof in a rectification column having from 10 to 100 theroretical plates and with a reflux ratio of from 2 to 100;
- said stereo isomeric mixture being one of the following mixtures:
- i. a mixture of .DELTA..sup.4,8 -cis- and .DELTA..sup.4 -trans-.DELTA..sup.8 -cis-farnesylacetic acids or esters thereof,
- ii. a mixture of .sup.4,8 -trans- and .sup.4 -cis-.sup. 8 -trans-farnesylacetic acids or esters thereof, or
- iii. a mixture of four isomers of .DELTA..sup.4,8 -cis-, .DELTA..sup.4 -trans-.DELTA..sup.8 -cis-, .DELTA..sup.4 -cis-.DELTA..sup.8 -trans- and .DELTA..sup.4,8 -trans-farnesylacetic acids or esters thereof,
- to separate each stereospecific farnesylacetic acid or ester thereof from the mixture of (i) or (ii), or to separate .DELTA..sup.4,8 -trans- or .DELTA..sup.4,8 -cis-farnesylacetic acid or ester thereof from the mixture of (iii).
A process for preparing a stereospecific farnesylacetic acid ester, at .DELTA..sup.4 and .DELTA..sup.8 positions, having the formula:
- ##STR21## wherein R.sub.1 represents a lower alkyl radical having 1 to 6 carbon atoms, a lower cycloalkyl radical having 3 to 6 carbon atoms, a lower alkenyl radical having 2 to 6 carbon atoms, or a lower cycloalkenyl radical having 3 to 6 carbon atoms, which comprises:
- 1. rectifying a mixture of .DELTA..sup.6 -cis- and .DELTA..sup.6 -trans-nerolidols to separate each one of them,
- 2. reacting said .DELTA..sup.6 -cis- or .DELTA..sup.6 -trans-nerolidol with an orthoacetic acid ester having the formula
- CH.sub.3 C(OR.sub.1).sub.3
- wherein R.sub.1 is the same as described above, in the presence of an acidic catalyst to produce
- i. a mixture of .DELTA..sup.4,8 -cis- and .DELTA..sup.4 -trans-.DELTA..sup.8 -cis-farnesylacetic acid ester from .DELTA..sup.6 -cis-nerolidol, or
- ii. a mixture of .DELTA..sup.4,8 -trans- and .DELTA..sup.4 -cis-.DELTA..sup.8 -trans-farnesylacetic acid ester from .DELTA..sup.6 -trans-nerolidol, and
- 3. rectifying said mixture (i) or (ii) to separate each one of said isomers, respectively.
Dependencies are inferred from the claim text.