The present invention is a fragrance precursor of formula I:
1
for a fragrant ketone of formula II:
2
and a fragrant ester of formula III:
3
wherein,
R
1
to R
5
represent independently H, —NO
2
, linear or branched C
1
-C
6
-alkyl, C
1
-C
6
-alkenyl, C
1
-C
6
-alkinyl or C
1
-C
4
-alkoxy,
R
1
and R
2
, R
2
and R
3
, R
3
and R
4
, and R
4
and R
5
may form together one or two aliphatic or aromatic rings,
R
6
and R
7
are independently H, linear or branched C
1
-C
6
-alkyl-, C
1
-C
6
-alkenyl, C
1
-C
6
-alkinyl, and
R
8
and R
9
are the residues of an acid R
8
-COOH and an alcohol R
9
OH respectively forming the fragrant ester of formula III. A method for providing an odor by admixing with a product a fragrance precursor as detailed above.
Phosphonyl radical addition to enol ethers. The stereoselective synthesis of cyclic ethers
作者:Christopher M. Jessop、Andrew F. Parsons、Anne Routledge、Derek J. Irvine
DOI:10.1016/j.tetlet.2004.04.173
日期:2004.6
Addition of diethyl phosphite or diethyl thiophosphite to enol ethers, in the presence of a radical initiator, results in the regioselective synthesis of organophosphonate or phosphonothioate derivatives, respectively, under mild conditions. This method can be applied to the stereoselective formation of substituted tetrahydrofurans and tetrahydropyrans, on cyclisation of vinyl ethers bearing unsaturated