Synthesis of deuterium-labeled derivatives of dimethylallyl diphosphate

Article abstract of DOI:10.1021/jo052384n

Short practical syntheses for five deuterium-labeled derivatives of dimethylallyl diphosphate (DMAPP) useful for enzymological studies are reported. These include the preparation of the C1-labeled derivatives (R)-[1- ²H]3-methylbut-2-enyl diphosphate ((R)-[1-²H]1-OPP) and (S)-[1-²H]3-methylbut-2-enyl diphosphate ((S)-[1-²H]1-OPP) , the C2-labeled derivative [2-²H]3-methylbut-2-enyl diphosphate ([2-²H]1-OPP), and the methyl-labeled derivatives (E)-[4,4,4- ²H₃]3-methylbut-2-enyl diphosphate ((E)-[4,4,4- ²H₃]1-OPP) and (Z)-[4,4,4-²H ₃]3-methyl-but-2-enyl diphosphate ((Z)-[4,4,4-²H ₃]1-OPP).

Full text of DOI:10.1021/jo052384n

SCHEME 1. Synthesis of (R)- and (S)-[1-2H]1-OPPa
Synthesis of Deuterium-Labeled Derivatives of
Dimethylallyl Diphosphate
Hirekodathakallu V. Thulasiram, Richard M. Phan,
Susan B. Rivera, and C. Dale Poulter*
315 South 1400 East RM 2020, Department of Chemistry,
UniVersity of Utah, Salt Lake City, Utah 84112
poulter@chemistry.utah.edu
ReceiVed NoVember 18, 2005
a Key: (a) LiAlD4, rt, 2 h, 86%; (b) PCC, CH2Cl2, rt, 3 h, 78%; (c)
S-BITIP, Bu3SnH, Et2O, -20 °C, 24 h, 70%; (d) bis-triethylammonium
phosphate (TEAP), CCl3CN, CH3CN, rt, 15 min, 30%; (e) R-BITIP,
Bu3SnH, Et2O, -20 °C, 24 h, 69%.
Short practical syntheses for five deuterium-labeled deriva-
tives of dimethylallyl diphosphate (DMAPP) useful for
enzymological studies are reported. These include the
preparation of the C1-labeled derivatives (R)-[1-2H]3-meth-
ylbut-2-enyl diphosphate ((R)-[1-2H]1-OPP) and (S)-[1-2H]3-
methylbut-2-enyl diphosphate ((S)-[1-2H]1-OPP), the C2-
labeled derivative [2-2H]3-methylbut-2-enyl diphosphate ([2-
2H]1-OPP), and the methyl-labeled derivatives (E)-[4,4,4-
2H3]3-methylbut-2-enyl diphosphate ((E)-[4,4,4-2H3]1-OPP)
and (Z)-[4,4,4-2H3]3-methyl-but-2-enyl diphosphate ((Z)-
[4,4,4-2H3]1-OPP).
stereochemistries of these reactions are best studied with
isotopically labeled derivatives of the normal substrates. We
now report short practical routes for the stereoselective synthesis
of deuterated derivatives of DMAPP, which collectively place
labels at each of the carbons bearing hydrogen atoms.
The syntheses of (R)-[1-2H]3-methyl-2-butenyl diphosphate
((R)-[1-2H]1-OPP) and (S)-[1-2H]3-methyl-2-butenyl diphos-
phate ((S)-[1-2H]1-OPP) are outlined in Scheme 1. [1-2H]3-
Methyl-2-butenal ([1-2H]3)5 was reduced with BITIP catalysts
derived from (S)- and (R)-BINOL and Bu3SnH6 to give (R)-
[1-2H]1-OH and (S)-[1-2H]1-OPP, respectively. The 1H NMR
spectra of (R)- and (S)-[1-2H]1-OH were similar to that reported
for the S enantiomer obtained by a fermenting yeast reduction
of [1-2H]3.7 A portion of each alcohol was converted to the
corresponding Mosher ester.8,9 The C1 protons in the 1H NMR
spectra of the diastereomeric esters from (R)- and (S)-[1-2H]1-
OH and (R)-(-)-Mosher’s chloride were cleanly resolved,
giving peaks at 4.77 and 4.82 ppm, respectively. A comparison
of peak intensities indicated that the enantiomeric ratios for (R)-
and (S)-[1-2H]1-OH were 96/4 and 94.5/5.5, respectively.
Diphosphates (R)- and (S)-[1-2H]1-OPP were synthesized from
corresponding chiral alcohols by treatment with trichloroaceto-
nitrile and inorganic phosphate,10 a procedure that does not alter
the absolute stereochemistry of C1.
Isoprenoid compounds constitute a large diverse class of
“small molecule” natural products with over 35 000 individual
known metabolites. The vast majority of these compounds are
ultimately derived from two fundamental isoprenoid building
blocks, isopentenyl diphosphate (IPP) and dimethylallyl diphos-
phate (DMAPP, 1-OPP). DMAPP is the electrophilic primer
required to initiate the 1′-4 (head-to-tail) chain elongation
reactions for the biosynthesis of polyisoprenoid compounds,1
which are generated by successive alkylations of IPP by a
growing allylic diphosphate chain.2,3 DMAPP is also the
substrate for biosynthesis of monoterpenes with non-head-to-
tail skeletons4 and a variety of metabolites where the dimethyl-
allyl moiety is attached to nonisoprenoid fragments.1
[2-2H]3-methyl-2-butenyl diphosphate ([2-2H]1-OPP) was
prepared from ethyl acetoacetate (4) as shown in Scheme 2.
Deuterium was introduced at the C2 position of the â-ketoester
by two exchanges with D2O to give ∼96% exchange of the
two methylene hydrogens. The labeled keto ester was then
The prenyl-transfer enzymes that catalyze electrophilic alky-
lation reactions with DMAPP are typically highly stereoselec-
tive. Because many enzymes do not tolerate substitutions that
substantially increase the steric bulk of the substrates, the
(5) Vassilikogiannakis, G.; Chronakis, N.; Orfanopoulos, M. J. Am.
Chem. Soc. 1998, 120, 9911-9920.
* Corresponding author. Phone: 801-581-6685. Fax: 801-581-4391.
(1) Poulter C. D. Acc. Chem. Res. 1990, 23, 70-77.
(2) Kellogg, B. A. Poulter, C. D. Curr. Opin. Chem. Biol. 1997, 4, 570-
578.
(3) Koyama, T. Ogura, K. In ComprehensiVe Natural Products Chem-
istry: Isoprenoids; Cane, D. E., Ed.; Elsevier Science: Oxford, 1998; Vol.
2, p 73-96.
(4) Rivera, S. B.; Swedlund, B. D.; King, G. J.; Bell, R. N.; Hussey, C.
E.; Shattuck-Eidens, D. M.; Wrobel, W. M.; Peiser, G. D.; Poulter, C. D.
Proc. Natl. Acad. Sci. U.S.A. 2001, 98, 4373-4378.
(6) Keck, G. E.; Krishnamurthy, D. J. Org. Chem. 1996, 61, 7638-
7639.
(7) King, C. H. R.; Poulter, C. D. J. Am. Chem. Soc. 1982, 104, 1413-
4120.
(8) Dale, J. A.; Dull, D. L.; Mosher, H. S. J. Org. Chem. 1969, 34, 2543-
2549.
(9) Gao, Y.; Hanson, R. M.; Klunder, J. M.; KO, S. Y.; Masamune, H.;
Sharpless, K. B. J. Am. Chem. Soc. 1987, 109, 5765-5780.
(10) Keller, R. K.; Thompson, R. J. Chromatogr. 1993, 645, 161-167.
10.1021/jo052384n CCC: $33.50 © 2006 American Chemical Society
Published on Web 01/25/2006
J. Org. Chem. 2006, 71, 1739-1741
1739

SCHEME 2. Synthesis of [2-2H]1-OHa
SCHEME 3. Synthesis of (E)- and (Z)-[4,4,4-2H3]1-OPPa
a Key: (a) D2O, rt, 24 h, two times, 92%; (b) NaH, ClPO(OEt)2, Et2O,
0 °C, 2 h, 89%; (c) Me2CuLi, Et2O, -47 °C, 2 h, 93%; (d) DIBAL, Et2O,
-70 0 °C, 3 h, 84%; (e) PBr3, Et2O, 2 h, 81%; (f) tris(tetra-n-
butylammonium) hydrogen diphosphate, CH3CN, 34%.
converted to enol phosphate [2-2H]5 followed by treatment with
lithium dimethyl cuprate to give [2-2H]211 with a 2H content of
93%. The allylic ester was treated with DIBAL to give [2-2H]1-
OH. The allylic alcohol was converted into the corresponding
diphosphate by the well-established two-step halogenation/
phosphorylation procedure for synthesis of allylic diphos-
phates.12
a Key: (a) PhSH, NaOH, EtOH, rt, 4 h; (b) CD3MgBr, CuI, THF, -65
°C, 3 h, 81%/87%; (c) LiAlH4, Et2O, 0 °C, 2.5 h, 82%/75%; (d) NCS,
CH2Cl2, DMS, 78%/82%; (e) Tris(tetra-n-butylammonium) hydrogen
diphosphate, CH3CN, 60%/63%.
Syntheses of (E)-[4-2H3]3-methyl-2-butenyl diphosphate
((E)-[4,4,4-2H3]1-OPP) and (Z)-[4-2H3]3-methyl-2-butenyl diphos-
phate ((Z)-[4,4,4-2H3]1-OPP) are shown in Scheme 3. Although
both compounds have been prepared previously,13,14 the route
we report is an efficient divergent synthesis that yields both
stereoisomers. Benzenethiol was added to acetylenic ester 7 to
give a 95% yield of a ∼3:1 mixture of (E)- and (Z)-8, which
were readily separated by column chromatography. The geom-
etries of (E)- and (Z)-8 were assigned from the chemical shift
of the methyl15 and olefinic protons.16 In the 1H NMR spectrum
of the major isomer (E)-8, the olefinic proton and methyl protons
gave peaks at 5.26 and 2.43 ppm, respectively. For (Z)-8, the
corresponding resonances were observed at 5.85 and 1.81 ppm,
respectively. Treatment of the isomeric thioenol ethers with CD3-
MgBr in the presence of CuI gave the corresponding R,â-
unsaturated esters. Treatment of (E)- and (Z)-[4,4,4-2H3]4 with
LAH gave allylic alcohols (E)- and (Z)-[4,4,4-2H3]1-OH,
respectively. The corresponding diphosphates were prepared by
halogenation/phosphorylation.12
and oven-dried 4 Å molecular sieves (8 g) in ether was heated at
reflux for 1 h. The solution was cooled to room temperature, and
[1-2H]3 (1.02 g, 12 mmol) was added. The mixture was stirred for
5 min and cooled to -78 °C before Bu3SnH (4.19 g, 14.4 mmol)
was added. The mixture was stirred for 10 min and then placed in
6
a -20 °C freezer for 24 h. The usual workup
and flash
chromatography on silica gel with 3% ether in pentane gave (R)-
[1-2H]1-OH as a colorless oil: 0.73 g (70%; >99% 2H); 1H NMR
(CDCl3) δ 1.67 (s, 3H) 1.74 (s, 3H), 4.10 (d, J ) 6.9 Hz, 1H),
5.40 (d, J ) 7.2 Hz, 1H); 13C NMR (CDCl3) δ 18.0, 25.9, 59.2,
123.7, 136.7; mass spectrum m/z (rel intensity) 87 (28), 72 (100),
2
54 (20), 49 (25), 42 (23); HRMS (EI) calcd for C5H9 HO (M+)
87.0793, found 87.0796.
Following the same procedure with (R)-BINOL gave (S)-[1-2H]1-
2
1
OH7 as a colorless oil: 0.72 g (69% yield; >99% H); H NMR
(CDCl3) δ 1.67 (s, 3H) 1.73 (s, 3H), 4.10 (d, J ) 6.9 Hz, 1H),
5.39 (d, J ) 7.2 Hz, 1H); 13C NMR (CDCl3) δ 18.0, 25.9, 59.1,
123.7, 136.6; mass spectrum m/z (rel intensity) 87 (29), 72 (100),
2
54 (18), 42 (23); HRMS (EI) calcd for C5H9 HO (M+) 87.0793,
In summary, we report short practical syntheses for five
labeled derivatives of DMAPP where deuterium is stereospe-
cifically incorporated at specific protonated carbons in the
molecule.
found 87.0799.
Ethyl [2-2H]3-Methyl-2-butenoate ([2-2H]2). To a solution of
lithium dimethylcuprate (40 mmol, 2 equiv) in ether, cooled to -47
°C, was added enol phosphate [2-2H]5 (5.3 g, 20.0 mmol), and the
mixture was stirred at -47 °C. After 2 h, the mixture was poured
into an ice-cold mixture of 50% aqueous NH4Cl and concd NH4-
OH (5:1) and the aqueous phase was extracted with ethyl ether.
The combined ether extracts were washed with brine, dried over
MgSO4, and concentrated. Flash chromatography on silica gel (CH2-
Experimental Section
(R)- and (S)- [1-2H]3-Methyl-2-buten-1-ol ((R)- and (S)-[1-
2H]1-OH). A mixture of (S)-BINOL (1.14 g, 4.0 mmol), Ti(O-
iPr)4 (1.2 mL, 1.2 mmol), CF3COOH (1.2 mL of 0.5 M in CH2Cl2),
(14) Shibuya, M.; Chou, H. M.; Fountoulakis, M.; Hassam, S.; Kim, S.
U.; Kobayashi, K.; Otsuka, H.; Rogalska, E.; Cassady, J. M.; Floss, H. G.
J. Am. Chem. Soc. 1990, 112, 297-304.
(11) Sum, F. M.; Weiler, L. Tetrahedron, Suppl. 1 1981, 37, 303-317.
(12) Davisson, V. J.; Woodside, A. B.; Neal, T. R.; Stremler, K. E.;
Muehlbacher, M.; Poulter, C. D. J. Org. Chem. 1986, 51, 4768-4779.
(13) Mohanty, S. S.; Uebelhart, P.; Eugster, C. H. HelV. Chim. Acta 2000,
83, 2036-2053.
(15) Hill, R. K.; Yan, S.; Arfin, S. M. J. Am. Chem. Soc. 1973, 95, 7857-
7859.
(16) Mori, K.; Mori, H. Tetrahedron 1987, 43, 4097-4106.
1740 J. Org. Chem., Vol. 71, No. 4, 2006

Cl2) gave 2.13 g (93% yield, 93% 2H) of a colorless oil: 1H NMR
(CDCl3) δ 1.27 (t, J ) 7.2 Hz, 3H,), 1.88 (s, 3H), 2.16 (s, 3H),
4.13 (2H, q, J ) 7.2 Hz); 13C NMR (CDCl3) δ 14.5, 20.3, 27.5,
59.6, 116.3, 156.5, 166.9; mass spectrum m/z (rel intensity) 129
(4), 72 (18), 57 (16), 43 (100); HRMS (EI) calcd for C7H112HO2
(M+) 129.0899, found 129.0920.
Following the same procedure, 3.00 g (0.014 mol) of (Z)-8 gave
(Z)-[4,4,4-2H3]4 as a colorless oil: 1.54 g (87% yield, >99% 2H3);
1H NMR14,15 (CDCl3) δ 1.28 (t, J ) 7.2 Hz, 3H), 1.89 (d, J ) 1.0
Hz, 3H), 4.15 (t, J ) 7.2 Hz, 2H), 5.68 (d, J ) 1 Hz, 1H); 13C
NMR (CDCl3) δ 14.5, 27.5, 59.6, 116.4, 156.7, 166.9; HRMS (CI)
2
[M + 1]+ calcd for C7H9 H3O2 132.1100, found 132.1107.
Ethyl (E)- and (Z)-[4-2H3]3-Methyl-2-butenoate ((E)- and (Z)-
[4,4,4-2H3]4). To a stirred suspension of CuI (5.1 g, 0.03 mol) in
dry THF at -63 °C was added CD3MgI (67 mL of 1 M, 0.07 mol)
in ether. After the mixture was stirred for 15 min at -63 °C, a
solution of E-8 (3.00 g, 0.014 mol) in dry THF was added, and
stirring was continued for 3 h. The mixture was then poured into
satd NH4Cl and stirred for 15 min at rt. The aqueous layer was
extracted with ether. The combined organic layers were washed
with 5% NaOH, water, and brine, dried over MgSO4, filtered, and
concentrated in vacuo. The residue was chromatographed over silica
Acknowledgment. This study was supported by NIH Grant
No. GM 21328.
Supporting Information Available: General experimental
details, characterization data for all compounds (except (R)- and
1
(S)-[1-2H]1-OH, [2-2H]2, and (E)- and (Z)-[4,4,4-2H3]4) and H
and 13C or 31P spectra for (R)- and (S)-[1-2H]1-OH, (R)- and (S)-
[1-2H]1-OPP, [2-2H]5, [2-2H]2, [2-2H]1-OH, [2-2H]1-OPP, (E)-
8, (Z)-8, and (E)-[4,4,4-2H3]4. This material is available free of
charge via the Internet at http://pubs.acs.org.
2
(9:1 hexane/ether) to give 1.43 g (81% yield, >99% H3) of a
colorless oil: 1H NMR (CDCl3) δ 1.27 (t, J ) 7.2 Hz, 3H), 2.17
(d, J ) 1.2 Hz, 3H), 4.15 (q, J ) 7.2 Hz, 2H), 5.67 (d, J ) 1.2 Hz,
1H); 13C NMR (CDCl3) δ 14.5, 20.3, 59.6, 116.3, 156.6, 166.9;
HRMS (CI) [M + 1]+ calcd for C7H9 H3O2 132.1100, found
2
132.1108.
JO052384N
J. Org. Chem, Vol. 71, No. 4, 2006 1741