A new approach to 1-substituted-1,2-alkadiene-phosphonates III: Synthesis of 2-keto-5-methyl-3,4-hexadienyl-3-phosphonate dimethyl esters

Article abstract of DOI:10.1080/104265090917628

Abstract: The synthesis of the titled compounds have been discussed. Copyright Taylor & Francis Inc.

Full text of DOI:10.1080/104265090917628

This article was downloaded by: [The Aga Khan University]
On: 20 October 2014, At: 23:37
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954
Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH,
UK
Phosphorus, Sulfur, and Silicon
and the Related Elements
Publication details, including instructions for
authors and subscription information:
http://www.tandfonline.com/loi/gpss20
A New Approach to 1-
Substituted-1,2-Alkadiene-
Phosphonates III: Synthesis
of 2-Keto-5-Methyl-3,4
Hexadienyl-3-Phosphonate
Dimethyl Esters
D. D. Enchev a
a Department of Organic Chemistry , K. Preslavski
University , Shoumen, Bulgaria
Published online: 19 Aug 2006.
To cite this article: D. D. Enchev (2005) A New Approach to 1-Substituted-1,2-
Alkadiene- Phosphonates III: Synthesis of 2-Keto-5-Methyl-3,4 Hexadienyl-3-
Phosphonate Dimethyl Esters, Phosphorus, Sulfur, and Silicon and the Related
Elements, 180:9, 2127-2130, DOI: 10.1080/104265090917628
To link to this article: http://dx.doi.org/10.1080/104265090917628
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the
information (the “Content”) contained in the publications on our platform.
However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness,
or suitability for any purpose of the Content. Any opinions and views
expressed in this publication are the opinions and views of the authors, and
are not the views of or endorsed by Taylor & Francis. The accuracy of the
Content should not be relied upon and should be independently verified with
primary sources of information. Taylor and Francis shall not be liable for any

losses, actions, claims, proceedings, demands, costs, expenses, damages,
and other liabilities whatsoever or howsoever caused arising directly or
indirectly in connection with, in relation to or arising out of the use of the
Content.
This article may be used for research, teaching, and private study purposes.
Any substantial or systematic reproduction, redistribution, reselling, loan,
sub-licensing, systematic supply, or distribution in any form to anyone is
expressly forbidden. Terms & Conditions of access and use can be found at
http://www.tandfonline.com/page/terms-and-conditions

Phosphorus, Sulfur, and Silicon, 180:2127–2130, 2005
Copyright © Taylor & Francis Inc.
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/104265090917628
A New Approach to 1-Substituted-1,2-Alkadiene-
Phosphonates III: Synthesis of 2-Keto-5-Methyl-3,4-
Hexadienyl-3-Phosphonate Dimethyl Esters
D. D. Enchev
Department of Organic Chemistry, K. Preslavski University, Shoumen,
Bulgaria
The synthesis of the titled compounds have been discussed.
Keywords Acetylenic diols; allenephosphonates; Jones reagent
INTRODUCTION
The phosphorylated allenes, which are easily prepared via acetylen-
allene rearrangement of acetylene phosphites,1 contain a system of dou-
ble bonds which provide an unusual character of their interactions with
numerous electrophiles and nucleophiles.1
Numerous investigations show that allenephosphonates have to be
taken in consideration as precursors for the synthesis of many inter-
esting compounds, which preparations are restricted, to some extent,
by using other approaches.2−5
On the other hand, the discovered oxaphospholic cyclization of the
allenephosphonates in the reaction with electrophilic reagents gives
cyclic compounds, in many cases with very interesting properties6−8
from a practical point of view.
In this article, we report our results on the synthesis of different 1-
keto-substituted derivatives using the acetylene-allene rearrangement
of α-substituted acetylenic compounds.
RESULTS AND DISCUSSION
Continuing our investigations of the chemical behavior of 1-substituted
1,2-alkadienephosphonates, we successfully synthesized at C1
Received November 26, 1997; accepted November 4, 2004.
Note from the editor: Due to unknown reasons, this manuscript was not published in
1997.
Address correspondence to D. D. Enchev, K. Preslavski University, Department of
Organic Chemistry, Faculty of Chemistry, Shoumen 9700, Bulgaria. E-mail: rector@
shu-bg.net
2127

2128
D. D. Enchev
keto-substituted allenephosphonate derivatives. Using the procedure
described earlier for the oxidation of the secondary silylated alcohols,
we obtained α-keto acetylenic alcohols, which smoothly react with
chlorophosphites to 1-keto-substituted-1,2-alkadienephosphonates.
The reaction was carried out following the procedures described,
involving in the first step a silylation of the secondary acetylenic diol,
oxidation of the sylilated hydroxyl group using the Jones reagent10
and interaction finally with dialkylchlorophosphites (see Experimental
section). The reaction follows Scheme 1:
SCHEME 1
Thus, new precursors for the synthesis of kumulatriene derivatives
by the Wittig-Horner-Emmons reaction have been synthesized.
EXPERIMENTAL
Analytical Methods
1H nmr spectra were determined on a Tesla BS(80 MHz) at normal
temperature as CDCl3 solution with TMS as an internal standard.
The IR spectra were recorded on an IR-72-spectrophotometer (Carl
Zeiss Jena).
Starting Materials
The acetylenic diols are commercially available from Fluka, Switzer-
land.
1. Synthesis of Sylilated Acetylenic Diols
General Procedure. To a solution of the acetylenic diol and triethy-
lamine in dry benzene an equimolar amount of TMSCI in the same

Allenephosphonates
2129
TABLE I Constants and Elemental Analysis Data for
Compounds 2a–d
No. R R1
R2
Yield (%)
85
Fond % P
15.12
Formula
Calcd. % P
15.17
2a
b
Me
H
Et
Me
C8H13O4P
Me
Me
Me
87
92
95
13.25
11.87
11.88
C10H17O4P
13.34
11.9
11.9
H
c
n-Pr
H
C
C
12H21O4P
12H21O4P
d
i-Pr
H
solvent was added dropwise. The resulting mixture was heated to 50◦C
and then allowed to reach room temperature. After filtration of the tri-
ethylaminehydrochloride and evaporation of the solvent, the residue
was distilled. Yield 85–90%.
2. Oxidation of the Silylated Diols
General Procedure. To a solution of the silylated diol in acetone at
0◦C a solution prepared from CrO3H20 and H2SO4 was added. After
appropriate work-up (see references) the crude ketone was distilled.
Yield 78–80%.
TABLE II 1H-, 31P and IR Spectral Data
for Compounds 2a–d
IR spectra (cm−1
)
No. R(R2)
R1
31p
C
O
P O
2a
Me
(Me)
H
0.67
1.34
5.02
16.8 1670
1235
b
Et
CH3-0.98 17.4 1660
1230
CH2-3.78
1.34
5.02
(Me)
H
c
n-Pr
CH3-0.89
CH2-3.77
1.34
17.8 1665
1234
1225
(Me)
H
i-Pr
5.02
d
CH3-0.90 18.4 1660
CH-0.65
1.34
5.02
(Me)
H

2130
D. D. Enchev
3. Synthesis of 1-Ketosubstituted-1,2-alkadienephosphonates
General Procedure. To a solution of the ketone 3 in dry ether a solu-
tion of dialkylchlorophosphite and triethylamine was added dropwise
at −10◦C with stirring. After 24 hours the triethylamine hydrochlo-
ride was filtered off, the solvent was evaporaled, and the residue was
distilled.
Yield 68–70%. The elemental analysis and spectroscopic date are
given in Tables I and II.
REFERENCES
[1] V. Mark, In Selective Organic Transformations, B. S. Thyagarayan, Ed., New York:
Wiley (1970), p. 319.
[2] Ch. M. Angelov, Phosphorus and Sulfur, 15, 177 (1983); CA: 99, 53800m (1983).
[3] Ch. M. Angelov and D. D. Enchev, Phosphorus, Sulfur, and Silicon, and the Related
Elements, 37, 125 (1988).
[4] Ch. M. Angelov, and D. D. Enchev, Phosphorus, Sulfur, and Silicon, and the Related
Elements, 34, 163 (1988).
[5] D. D. Enchev, Ch. M. Angelov, et al., Phosphorus, Sulfur, and Silicon, and the Related
Elements, 57, 249 (1991).
[6] R. S. Macomber and G. A. Krudy, J. Org. Chem., 48, 1420 (1983).
[7] L. Homer and V. Binder, Phosphorus, 1, 17 (1971).
[8] P. Cadiot, W. Choddgfkiewicz, B. Borecka, C. Charier, and M.-P. Simmonnian, Chem.
Abstr., 67, 116923r (1967).
[9] R. S. Macomber and T. C. Hemling, Israel J. of Chemistry, 26, 136 (1985).
[10] R. Baker, V. Bhaskar Rao, P. D. Ravenscroft, and C. J. Swain, Synthesis, 572 (1983).