Synthesis of (8E, 10Z)-tetradeca-8, 10-dienal, sex pheromone of horse chestnut leafminer (Cameraria ohridella), and all its geometrical isomers

Article abstract of DOI:10.1135/cccc20000511

(8E,10Z)-Tetradeca-8, 10-dienal (1a), sex pheromone of the horse chestnut leafminer (Cameraria ohridella; Lepidoptera, Gracillariidae), and its geometrical isomers (1b-1d) were efficiently synthesized using tetrakis(triphenylphosphine)palladium catalyzed cross-coupling reactions of alk-1-ynes or alkenyl alanes with corresponding vinyl iodides. The stereoisomeric purity of obtained tetradecadienals 1a-1d was higher than 95% (GC). Relative electroantennographic (EAG) activities of the prepared compounds 1a-1d elicited on male antennae supported the previously published identification of the C. ohridella sex pheromone.

Full text of DOI:10.1135/cccc20000511

(8E,10Z)-Tetradeca-8,10-dienal
511
SYNTHESIS OF (8E,10Z)-TETRADECA-8,10-DIENAL, SEX PHEROMONE
OF HORSE CHESTNUT LEAFMINER (Ca m era ria ohridella ),
AND ALL ITS GEOMETRICAL ISOMERS
1
2
3,
Michal HOSKOVEC , David ŠAMAN and Aleš SVATOŠ *
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic,
1
Flemingovo nám. 2, 166 10 Prague 6, Czech Republic; e-mail: hoskovec@uochb.cas.cz,
2
saman@uochb.cas.cz, 3svatos@uochb.cas.cz
Received February 25, 2000
Accepted March 24, 2000
Dedicated to Professor Otakar Červinka on the occasion of his 75th birthday in recognition of his
outstanding contribution to the stereochemistry of organic compounds.
(8E,10Z)-Tetradeca-8,10-dien al (1a ), sex ph erom on e of th e h orse ch estn ut leafm in er
(Cameraria ohridella; Lepidoptera, Gracillariidae), an d its geom etrical isom ers (1b–1d ) were
efficien tly syn th esized usin g tetrakis(triph en ylph osph in e)palladium catalyzed cross-couplin g
reaction s of alk-1-yn es or alken yl alan es with correspon din g vin yl iodides. Th e stereo-
isom eric purity of obtain ed tetradecadien als 1a–1d was h igh er th an 95% (GC). Relative
electroan ten n ograph ic (EAG) activities of th e prepared com poun ds 1a–1d elicited on m ale
an ten n ae supported th e previously publish ed iden tification of th e C. ohridella sex
ph erom on e.
Key w ord s: Con jugated dien als; Stereoselective syn th esis; Negish i reaction ; Sex ph erom on es;
Cameraria ohridella; Cross-couplin g reaction s; Alken es; Dien es.
Durin g th e last 10 years, th e h orse ch estn ut leafm in er1, Cameraria ohridella
Desch ka an d Dim ić, 1986 (Lepidoptera, Gracillariidae), a m oth of yet un -
kn own origin , spread over vast areas of Cen tral an d Eastern Europe2. Th e
larvae of th is species develop in side th e h orse ch estn ut (Aesculus
hippocastanum L.) leaves wh ere th ey con sum e th e paren ch ym a. As a con se-
quen ce, leaves die soon , an d defoliation of trees starts in early sum m er.
Availability of a syn th etic sex ph erom on e of th is species could lead to en vi-
ron m en tally-safe pest m an agem en t.
Recen tly th e sex ph erom on e of C. ohridella was iden tified in our labora-
tory3,4. Th e con vergen t iden tification of th e ph erom on e usin g electro-
an ten n ograph ic (EAG) recordin gs em ployed h igh sen sitivity an d selectivity
of m ale an ten n ae to th e sex ph erom on e an d th eir structure an alogs. Con se-
Collect. Czech. Chem. Commun. (Vol. 65) (2000)

512
Hoskovec, Šaman, Svatoš:
quen tly, after determ in ation of th e fun ction al group (aldeh yde), th e ch ain
len gth (lin ear, 14 carbon atom s) an d ten tative assign m en t of th e position s
of double bon ds (8,10) we n eeded to prepare stereoisom ers of th e corre-
spon din g con jugated tetradecadien als. Here we are presen tin g th e prepara-
tion of (8E,10Z)-tetradeca-8,10-dien al (1a), th e iden tified sex ph erom on e of
C. ohridella an d its geom etric isom ers (1b–1d ). EAG recordin gs of th e iso-
m ers are also reported.
O
O
1a
1b
O
O
1c
1d
Th e key step of th e syn th esis of th e target com poun ds 1a–1d , a con struc-
tion of th e con jugated dien e m oiety, is based on tetrakis(triph en yl-
ph osph in e)palladium catalyzed C(sp)–C(sp2) an d C(sp2)–C(sp2) cross-
couplin g reaction s of alk-1-yn es or vin yl organ om etallics with vin yl
h alogen ides5–7. Th is “vin yl” cross-couplin g approach offers h igh isom eric
purity of products an d reason able yields in com parison with oth er syn -
th etic path s8 (for exam ple Wittig reaction ). An oth er advan tage is usin g th e
sam e in term ediates (pen t-1-yn e, 4, 13) an d ch em ical tran sform ation s in th e
syn th esis (Sch em e 1) of all four tetradecadien al isom ers 1a–1d .
EXPERIMENTAL
Ch em ical Syn th esis
Spectral methods: NMR spectra were determ in ed in CDCl3 solution s on
a Varian
UNITY-500 spectrom eter operatin g at 499.5 MHz for 1H an d at 125.7 MHz for 13C NMR, re-
spectively. Ch em ical sh ifts are expressed in δ (ppm ) scale relative to tetram eth ylsilan e for 1H
an d relative to CDCl3 sign al (77.00 ppm ) for 13C NMR, respectively. Couplin g con stan ts are
reported in Hz. Electron im pact (70 eV) m ass spectra were obtain ed on Fison s MD 800
GC/MS in strum en t.
Chromatography: GC an alyses were perform ed on
a Hewlett–Packard HP 6890 gas
ch rom atograph equipped with FID detector (275 °C), split/splitless in jection port (230 °C),
electron ic pressure con trol (EPC), an d HP 6890 autom atic in jector. A Hewlett–Packard HP-5
capillary colum n (30 m × 0.32 m m ; film th ickn ess 0.25 µm ) an d h elium gas (con stan t pres-
sure 66 kPa) were used for separation s. Th e tem perature program started at 100 °C, th en th e
tem perature of th e oven was in creased to 220 °C (rate 5 °C m in –1; 10 m in delay at 220 °C).
Preparative m edium -pressure liquid ch rom atograph y (PMPLC) separation s were m ade on
Merck 60 silica gel (0.040–0.063 m m ) usin g a Büch i B-680 Prep LC System with eth yl acetate
Collect. Czech. Chem. Commun. (Vol. 65) (2000)

(8E,10Z)-Tetradeca-8,10-dienal
513
or ben zen e in h exan e. Th e m obile ph ase for ch rom atograph y of th e sen sitive fin al products,
con jugated dien ic aldeh ydes 1a–1d , was spiked with trieth ylam in e (0.3% v/v).
Chemicals: All ch em ical reaction s were run in oven -dried glassware un der argon .
Tetrah ydrofuran (THF), h exan e an d ben zen e were distilled from sodium ben zoph en on e ketyl
in argon atm osph ere. Dich lorom eth an e was distilled from calcium h ydride an d stored over
m olecular sieves. All oth er ch em icals were used as purch ased. NMR spectra (13C NMR spectra
of dien als 1a–1d are presen ted separately in Table I) an d elem en tal an alyses of all syn th e-
sized com poun ds were fully con sisten t with th e proposed structures.
1-Brom o-7-(tert-butoxy)h eptan e (2)
Th e com poun d 2 was prepared by a stan dard m an n er9 from 7-brom oh eptan -1-ol (39.0 g,
0.20 m ol), 2-m eth ylpropen e (200 m l) an d Am berlyst H-15 (5.0 g). Yield 98% (49.2 g).
1H NMR (CDCl3): 1.18 s, 9 H (3 × CH3); 1.26–1.49 m , 8 H (4 × CH2); 1.50 m , 2 H
(–CH2CH2OR); 3.33 t, 2 H, J = 6.9 (–CH2OR); 3.40 t, 2 H, J = 2 × 6.8 (–CH2Br). For
C
11H23BrO (251.2) calculated: 52.59% C, 9.23% H, 31.81% Br; foun d: 52.66% C, 9.17% H,
31.68% Br.
9-(tert-Butoxy)n on -1-yn e10 (3)
To a stirred an d cooled (0 °C) suspen sion of lith ium acetylide–eth ylen ediam in e com plex
(20.0 g, 0.20 m ol) in an h ydrous dim eth yl sulfoxide (100 m l) was slowly (60 m in ) added
com poun d 2 (25.1 g, 0.10 m ol). Th e reaction m ixture was stirred at room tem perature for
6 h , th en it was poured in to ice water an d extracted with h exan e (4 × 100 m l). Th e com -
bin ed h exan e extracts were wash ed with water (3 × 100 m l), brin e (2 × 100 m l) an d dried
over K2CO3. Solven ts were evaporated, an d th e oily residue (22.3 g) was distilled in vacuo.
Th e distillation gave alkyn e 3 (18.0 g, 92%; b.p. 130–135 °C/1.33 kPa). 1H NMR (CDCl3):
1.18 s, 9 H (3 × CH3); 1.28–1.44 m , 8 H (4 × CH2); 1.52 m , 2 H (–CH2CH2OR); 1.93 t, 1 H,
J = 2.7 (HC≡C–); 2.18 dt, 2 H, J = 2.7, 2 × 7.2 (HC≡C–CH2–); 3.32 t, 2 H, J = 6.7 (–CH2OR).
For C13H24O (196.3) calculated: 79.53% C, 12.32% H; foun d: 79.38% C, 12.50% H.
(E)-9-(tert-Butoxy)-1-iodon on -1-en e11 (4)
A solution of alkyn e 3 (9.82 g, 50 m m ol) in h exan e (30 m l) was treated with diisobutyl-
alum in ium h ydride (DIBAH; 1 M solution in h exan es, 55 m l) at 55 °C for 5 h , cooled to –45 °C,
an d a solution of iodin e (12.94 g, 51 m m ol) in THF (30 m l) was added dropwise. After th e
addition , th e m ixture was stirred overn igh t at room tem perature. Th e reaction m ixture was
poured in to 200 m l of 6 M NaOH an d stirred un til th e brown color h ad disappeared. Organ ic
layer was separated an d th e aqueous on e was extracted with h exan e (3 × 100 m l). Th e or-
gan ic layers were collected, wash ed with water (3 × 75 m l) an d dried over an h ydrous K2CO3.
Th e crude product, obtain ed after evaporation of solven ts was purified by PMPLC (0.5%
eth yl acetate in h exan e) affordin g vin yl iodide 4 (11.6 g, 72%). 1H NMR (CDCl3): 1.18 s, 9 H
(3 × CH3); 1.26–1.42 m , 8 H (4 × CH2); 1.51 m , 2 H (–CH2CH2OR); 2.14 dq, 2 H, J = 1.5, 3 ×
7.2 (I–CH=CH–CH2–); 3.32 t, 2 H, J = 6.7 (–CH2OR); 5.96 dt, 1 H, J = 2 × 1.5, 14.4
(I–CH=CH–); 6.50 dt, 1 H, J = 2 × 7.2, 14.4 (I–CH=CH–). For C13H25IO (324.2) calculated:
48.16% C, 7.77% H; 39.14% I; foun d: 48.12% C, 7.92% H; 39.33% I.
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514
Hoskovec, Šaman, Svatoš:
(E)-14-(tert-Butoxy)tetradec-6-en -4-yn e (5)
Tetrakis(triph en ylph osph in e)palladium (0.60 g, 0.5 m m ol) was added at 20 °C to a solution
of iodide 4 (3.24 g, 10.0 m m ol) in ben zen e (25 m l). Th e m ixture was stirred for addition al
60 m in . A solution of pen t-1-yn e (1.66 g, 15.0 m m ol) in an h ydrous butylam in e (7.34 g, 100
m m ol) an d cuprous iodide (0.37 g, 2.0 m m ol) was added. After 2 h at room tem perature, th e
m ixture was diluted with eth er (150 m l) an d subsequen tly poured in to saturated aqueous
am m on ium ch loride (100 m l). Th e organ ic layer was wash ed with 20% aqueous am m on ia
(3 × 100 m l), brin e (2 × 100 m l), water (2 × 100 m l), an d dried over an h ydrous MgSO4. Re-
m oval of th e solven ts in vacuo an d purification of th e residue by PMPLC (0.5–1.5% of eth yl
acetate in h exan e) gave 2.38 g (90%) of en yn e 5. 1H NMR (CDCl3): 0.98 t, 3 H, J = 7.5
(CH3CH2–); 1.18 s, 9 H (3 × CH3); 1.25–1.39 m , 8 H (4 × CH2); 1.50 m , 2 H (CH3CH2–); 1.52 m ,
2 H (–CH2CH2OR); 2.07 dq, 2 H, J = 1.5, 3 × 7.1 (–CH=CHCH2–); 2.26 dt, 2 H, J = 1.2, 2 × 1.7
(–CH2C≡C–); 3.32 t, 2 H, J = 6.7 (–CH2OR); 5.45 m , 1 H, J = 4 × 1.7, 15.8 (–CH=CH–); 6.03 m ,
1 H, J = 4 × 1.7, 15.8 (–CH=CH–). For C18H32O (264.5) calculated: 81.75% C, 12.20% H;
foun d: 81.95% C, 12.08% H.
TABLE I
13C NMR data (δ in ppm ) for 8,10-tetradecadien als 1a–1d
Carbon
1a(E,Z)
1b(Z,Z)
1c(E,E)
1d (Z,E)
1
2
202.77
43.90
22.00
29.29
28.58
29.05
32.80
134.50
125.71
128.75
129.90
29.74
22.88
13.77
202.81
43,88
21.99
29.25
29.19
27.42
29.52
123.73
123.68
131.88
132.93
29.54
22.80
13.77
202.83
43.87
22.02
29.16
29.00
28.86
32.45
132.04
130.52
130.41
132.34
34.69
22.56
13.71
202.80
43.87
22.02
29.52
27.33
28.92
29.00
131.69
123.82
123.67
132.01
29.37
22.80
13.78
3
4
5
6
7
8
9
10
11
12
13
14
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(8E,10Z)-Tetradeca-8,10-dienal
515
(4Z,6E)-14-(tert-Butoxy)tetradeca-4,6-dien e (6)
A dicycloh exylboran e suspen sion was prepared in THF (30 m l) from boran e–dim eth yl sulfide
com plex (10 m ol l–1, 0.97 m l) an d cycloh exen e (1.59 g, 19.4 m m ol). Th e obtain ed wh ite sus-
pen sion was treated at 0 °C with a solution of en yn e 5 (2.33 g, 8.8 m m ol) in THF (10 m l).
Th e m ixture was warm ed to room tem perature, an d stirred for 4 h . Th e form ed vin ylboran e
was h ydrolyzed with glacial acetic acid (10 m l) at 20 °C for 12 h , th e reaction m ixture was
n eutralized with NaOH (20%, 20 m l), an d carefully treated with aqueous H2O2 (30%, 10 m l).
Th e product was extracted with h exan e (4 × 75 m l). Ch rom atograph y (PMPLC) in h exan e
yielded protected dien ol 6 (1.61 g, 69%) in 97.8% isom eric purity (GC). 1H NMR (CDCl3):
0.92 t, 3 H, J = 7.4 (CH3CH2–); 1.18 s, 9 H (3 × CH3); 1.24–1.36 m , 8 H (4 × CH2); 1.40 m ,
2 H, J = 5 × 7.4 (CH3CH2–); 1.51 m , 2 H (–CH2CH2OR); 2.09 bdq, 2 H, J = 1.5, 3 × 7.5
(–CH=CHCH2–); 2.14 dq, 2 H, J = 1.5, 3 × 7.5 (–CH2CH=CH–); 3.32 t, 2 H, J = 6.7 (–CH2OR);
5.30 bdt, 1 H, J = 2 × 7.5, 10.8 (–CH=CH–CH=CH–); 5.65 bdt, 1 H, J = 3 × 7.3, 15.0
(–CH=CH–CH=CH–); 5.95 dtt, 1 H, J = 0.8, 2 × 1.5, 2 × 10.9 (–CH=CH–CH=CH–); 6.29 ddq,
1 H, J = 3 × 1.5, 11.0, 15.0 (–CH=CH–CH=CH–). For C18H34O (266.5) calculated: 81.12% C,
12.86% H; foun d: 81.31% C, 13.12% H.
(8E,10Z)-Tetradeca-8,10-dien -1-ol (7)
To a solution of protected dien ol 6 (1.07 g, 4.0 m m ol) in eth er (20 m l) was added acetic an -
h ydride (2 m l), an d th en an h ydrous FeCl3 (65 m g, 0.40 m m ol). Th e dark brown solution
was stirred for 20 h at room tem perature. A saturated aqueous solution of Na2HPO4 (15 m l)
was added, an d th e m ixture was stirred for 2 h . Th e solid FePO4 was filtered off, an d th e
aqueous layer was extracted with eth er (3 × 40 m l). Th e collected organ ic ph ases were dried
over an h ydrous MgSO4, an d th en con cen trated. Th e red oily residue (1.03 g) was dissolved
in m eth an ol (10 m l) an d an aqueous solution of NaOH (0.60 g in 4 m l of water) was added.
Th e m ixture was stirred at 20 °C for 16 h , poured in to water (75 m l), an d extracted with
h exan e–eth er (3 : 2, 4 × 25 m l). Th e com bin ed extracts were dried (an h ydrous K2CO3), evap-
orated, an d th e dark residue (0.98 g) was purified by PMPLC. Ch rom atograph y (10% eth yl
acetate in h exan e) gave 0.69 g (82%) of E,Z–dien ol 7. 1H NMR (CDCl3): 0.92 t, 3 H, J = 7.4
(CH3CH2–); 1.25–1.39 m , 8 H (4 × CH2); 1.41 m , 2 H (CH3CH2–); 1.57 m , 2 H (–CH2CH2OR);
2.09 bdq, 2 H, J = 1.5, 3 × 7.1 (–CH=CHCH2–); 2.14 dq, 2 H, J = 1.6, 3 × 7.5 (–CH2CH=CH–);
3.65 t, 2 H, J = 6.6 (–CH2OH); 5.31 dtt, 1 H, J = 2 × 0.7, 2 × 7.5, 10.8 (–CH=CH–CH=CH–);
5.65 dtt, 1 H, J = 2 × 0.8, 2 × 7.1, 15.1 (–CH=CH–CH=CH–); 5.96 dtt, 1 H, J = 0.9, 2 × 1.6, 2 ×
10.9 (–CH=CH–CH=CH–); 6.30 ddq, 1 H, J = 3 × 1.5, 11.0, 15.1 (–CH=CH–CH=CH–). For
C
14H26O (210.4) calculated: 79.94% C, 12.46% H; foun d: 80.22% C, 12.50% H.
(8E,10Z)-Tetradeca-8,10-dien al (1a)
Dien ol
7 (210 m g, 1 m m ol) was in jected in to a stirred suspen sion of pyridin ium
ch loroch rom ate (PCC; 258 m g, 1.2 m m ol) an d an h ydrous sodium acetate (20 m g) in di-
ch lorom eth an e (2 m l). Th e m ixture was stirred at room tem perature for 90 m in , th en
poured in to 50 m l of eth er an d filtered th rough a com bin ed layer of n eutral alum in a/ch ar-
coal/Celite. A subsequen t evaporation of th e solven ts an d PMPLC (0.3% trieth ylam in e in
ben zen e–h exan e, 1 : 1) afforded 151 m g (72%) of th e pure (96%, GC) target com poun d,
dien al 1a. 1H NMR (CDCl3): 0.92 t, 3 H, J = 7.4 (CH3CH2–); 1.27–1.38 m , 6 H (3 × CH2); 1.40
m , 2 H, J = 5 × 7.4 (CH3CH2–); 1.63 m , 2 H (–CH2CH2CHO); 2.09 bdq, 2 H, J = 1.5, 3 × 7.1
Collect. Czech. Chem. Commun. (Vol. 65) (2000)

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Hoskovec, Šaman, Svatoš:
(–CH=CHCH2–); 2.14 dq, 2 H, J = 1.6, 3 × 7.5 (–CH2CH=CH–); 2.42 dt, 2 H, J = 2 × 6.5
(–CH2CHO); 5.31 dtt, 1 H, J = 2 × 0.7, 2 × 7.5, 10.8 (–CH=CH–CH=CH–); 5.65 dtt, 1 H, J =
2 × 0.8, 2 × 7.0, 15.1 (–CH=CH–CH=CH–); 5.95 dtt, 1 H, J = 0.9, 2 × 1.6, 2 × 10.9
(–CH=CH–CH=CH–); 6.30 ddq, 1 H, J = 3 × 1.5, 11.0, 15.1 (–CH=CH–CH=CH–); 9.76 t, 1 H,
J = 1.8 (–CHO). EI-MS, m/z (rel.%): 39 (11), 41 (33), 54 (23), 55 (27), 67 (100), 68 (18), 79 (33),
80 (13), 81 (50), 82 (21), 91 (16), 93 (14), 95 (26), 96 (18), 98 (19), 109 (14), 208 (9, M+• ).
For C14H24O (208.3) calculated: 80.71% C, 11.61% H; foun d: 80.37% C, 11.44% H.
(E)-9-Iodon on -8-en -1-ol (8)
Th e iodoalken ol 8 (2.50 g, 93%) was prepared from tert-butyl eth er 4 (3.23 g, 10.0 m m ol)
followin g th e above described stan dard deprotection procedure. 1H NMR (CDCl3): 1.28–
1.44 m , 8 H (4 × CH2); 1.56 m , 2 H (–CH2CH2OH); 2.05 m , 2 H, J = 1.5,
3 × 7.3
(I–CH=CHCH2–); 3.64 t, 2 H, J = 6.5 (–CH2OH); 5.97 dt, 1 H, J = 2 × 1.5, 14.4 (I–CH=CH–);
6.50 dt, 1 H, J = 2 × 7.2, 14.4 (I–CH=CH–). For C9H17IO (268.13) calculated: 40.31% C,
6.39% H, 47.33% I; foun d: 40.40% C, 6.11% H, 47.09% I.
1-(tert-Butyldim eth ylsilyloxy)-(E)-9-iodon on -8-en e (9)
A m ixture of th e iodoalken ol 8 (2.40 g, 9.0 m m ol), tert-butyl(ch loro)dim eth ylsilan e (1.42 g,
9.5 m m ol), an h ydrous pyridin e (0.77 m l, 9.5 m m ol) an d 4-(dim eth ylam in o)pyridin e (DAP;
10 m g) in dich lorom eth an e (50 m l) was stirred at room tem perature for 20 h . Th e reaction
m ixture was th en diluted with eth er (200 m l), wash ed with saturated NaHCO3 solution (3 ×
75 m l), brin e (2 × 75 m l), an d dried over an h ydrous K2CO3. Evaporation of th e solven ts an d
subsequen t ch rom atograph y (h exan e) afforded 2.98 g (87%) of vin yl iodide 9. 1H NMR
(CDCl3): 0.05 s, 6 H (2 × CH3); 0.89 s, 9 H (3 × CH3); 1.27–1.40 m , 8 H (4 × CH2); 1.50 m ,
2 H (–CH2CH2OR); 2.04 dq, 2 H, J = 1.5, 3 × 7.3 (I–CH=CHCH2); 3.59 t, 2 H, J = 6.6
(–CH2OR); 5.97 dt, 1 H, J = 2 × 1.5, 14.4 (I–CH=CH–); 6.50 dt, 1 H, J = 2 × 7.2, 14.4
(I–CH=CH–). For C15H31IOSi (382.4) calculated: 47.11% C, 8.17% H, 33.19% I, 7.34% Si;
foun d: 46.95% C, 7.90% H, 33.22% I, 7.26% Si.
(4E,6E)-14-[tert-Butyl(dim eth yl)silyloxy]tetradeca-4,6-dien e (10)
To a stirred h exan e (5 m l) solution of pen t-1-yn e (0.44 m l, 4.0 m m ol) DIBAH (1 M solution
in h exan es; 3.0 m l) was added at –50 °C. After th e addition was com pleted, th e reaction
m ixture was slowly warm ed to 50 °C an d th en stirred at th e sam e tem perature for 5 h . Th e
solution was tran sferred with a PTFE can n ula to a m ixture of vin yl iodide 9 (1.00 g, 2.6
m m ol), zin c ch loride (1 M solution in THF; 3.0 m l), an d [Pd(Ph 3P)4] (300 m g, 0.26 m m ol) in
THF (10 m l) at room tem perature. After 18 h stirrin g, th e m ixture was decom posed by th e
addition of 10% NaOH solution (at 20 °C). Extraction with pen tan e (3 × 20 m l), dryin g (an -
h ydrous K2CO3) of th e collected extracts an d evaporation produced a dark oily residue
(1.01 g). PMPLC gave silyl eth er 10 (650 m g) as a colorless oil in 76% yield. 1H NMR
(CDCl3): 0.05 s, 6 H (2 × CH3); 0.89 s, 9 H (3 × CH3); 0.90 t, 3 H, J = 7.0 (CH3CH2–);
1.28–1.40 m , 8 H (4 × CH2); 1.41 m , 2 H (CH3CH2–); 1.57 m , 2 H (–CH2CH2OR); 2.04 m , 4 H
(2 × –CH=CHCH2–); 3.57 t, 2 H, J = 6.6 (–CH2OR); 5.51–5.59 m , 2 H (–CH=CH–CH=CH–);
5.97–6.02 m , 2 H (–CH=CH–CH=CH–). For C20H40OSi (324.6) calculated: 74.00% C, 12.42% H,
8.65% Si; foun d: 73.79% C, 12.22% H, 8.46% Si.
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(8E,10E)-Tetradeca-8,10-dien -1-ol12,13 (11)
A m ixture of tetrabutylam m on ium fluoride (1 M solution in THF; 2 m l) an d silyl eth er 10
(600 m g, 1.85 m m ol) was stirred at room tem perature for 24 h . Th e reaction m ixture was
poured in to water (30 m l) an d extracted with h exan e–eth er (3 : 2). Collected extracts were
wash ed with brin e (2 × 25 m l), dried over an h ydrous MgSO4 an d evaporated. Purification of
th e residual by PMPLC (10% eth yl acetate in h exan e) afforded 328 m g (84%) of dien ol 11.
1H NMR (CDCl3): 0.90 t, 3 H, J = 7.1 (CH3CH2–); 1.28–1.41 m , 8 H (4 × CH2); 1.41 m , 2 H
(CH3CH2–); 1.57 m , 2 H (–CH2CH2OH); 2.04 m , 4 H (2 × –CH=CHCH2–); 3.64 t, 2 H, J = 6.6
(–CH2OH); 5.52–5.61 m , 2 H (–CH=CH–CH=CH–); 5.97–6.03 m , 2 H (–CH=CH–CH=CH–).
For C14H26O (210.4) calculated: 79.94% C, 12.46% H; foun d: 79.63% C, 12.55% H.
(8E,10E)-Tetradeca-8,10-dien al (1b)
Th e dien al 1b (161 m g, 77%) was prepared from dien ol 11 (210 m g, 1.0 m m ol) an d PCC
(258 m g, 1.2 m m ol) followin g th e above described procedure for th e preparation of com -
poun d 1a. Isom eric purity 97.5% (GC). 1H NMR (CDCl3): 0.90 t, 3 H, J = 7.0 (CH3CH2–);
1.29–1.38 m , 6 H (3 × CH2); 1.41 m , 2 H (CH3CH2–); 1.63 m , 2 H (–CH2CH2CHO); 2.04 m , 4 H
(2 × –CH=CHCH2–); 2.42 dt, 2 H, J = 1.8, 2 × 7.3 (–CH2CHO); 5.52–5.59 m, 2 H (–CH=CH–CH=CH–);
5.96–6.02 m , 2 H (–CH=CH–CH=CH–); 9.76 t, 1 H, J = 1.8 (–CHO). EI-MS, m/z (rel.%): 39
(13), 41 (38), 54 (20), 55 (25), 67 (100), 68 (16), 79 (31), 80 (13), 81 (45), 82 (17), 91 (14), 93 (12),
95 (20), 96 (14), 98 (19), 109 (11), 208 (5, M+• ). For C14H24O (208.3) calculated: 80.71% C,
11.61% H; foun d: 80.57% C, 11.80% H.
9-(tert-Butoxy)-1-iodon on -1-yn e (12)
A 9-(tert-butoxy)n on -1-yn e (3; 4.2 g, 21.4 m m ol) solution in THF (30 m l) was m etallated at
–50 to 0 °C with butyllith ium (1.6 M solution in h exan es; 13.4 m l) for 20 m in . Th e form ed
solution was cooled to –60 °C, a solution of iodin e (5.43 g, 21.4 m m ol) in THF (20 m l) was
added slowly, an d th e reaction m ixture was allowed to warm up to 20 °C. Th e obtain ed
wh ite suspen sion was diluted with eth er (50 m l) an d th en quen ch ed with saturated aqueous
am m on ium ch loride (50 m l). Th e organ ic layer was separated an d th e aqueous layer ex-
tracted with pen tan e (2 × 50 m l). Th e com bin ed organ ic ph ases were successively wash ed
with saturated aqueous Na2S2O3 (2 × 50 m l), brin e (2 × 50 m l), an d dried over an h ydrous
MgSO4. Th e m ixture was passed th rough a sh ort silica gel colum n (50 g) an d solven ts were
th en evaporated. Th e obtain ed iodide 12 (6.69 g, 97%) was used in th e n ext h ydroboration
step with out furth er purification .
(Z)-9-(tert-Butoxy)-1-iodon on -1-en e (13)
Th e vin yl iodide 12 (4.66 g, 72%) was prepared from alkyn e 12 (6.44 g, 20.0 m m ol), boran e–
dim eth yl sulfide com plex (10 m ol l–1, 2.0 m l) an d cycloh exen e (3.29 g, 40.0 m m ol) follow-
in g th e procedure for th e reduction of com poun d 5. 1H NMR (CDCl3): 1.18 s, 9 H (3 × CH3);
1.21–1.56 m , 8 H (4 × CH2); 1.51 m , 2 H (–CH2CH2OR); 2.13 m , 2 H (I–CH=CH–CH2–); 3.32 t,
2 H, J = 6.8 (–CH2OR); 6.13–6.18 m , 2 H (I–CH=CH–). For C13H25IO (324.2) calculated:
48.16% C, 7.77% H, 39.14% I; foun d: 47.87% C, 7.99% H, 38.91% I.
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(Z)-14-(tert-Butoxy)tetradec-6-en -4-yn e (14)
Th e en yn e 14 (1.75 g, 86%) was prepared from vin yl iodide 13 (3.24 g, 10.0 m m ol),
[Pd(Ph 3P)4] (600 m g, 0.5 m m ol), Cu2I2 (370 m g, 2.0 m m ol), an d pen t-1-yn e (1.66 g, 15.0
m m ol) followin g th e procedure for preparation of com poun d 5. 1H NMR (CDCl3): 1.01 t,
3 H, J = 7.4 (CH3CH2–); 1.18 s, 9 H (3 × CH3); 1.28–1.48 m , 8 H (4 × CH2); 1.52 m , 2 H
(CH3CH2–); 1.57 m , 2 H (–CH2CH2OR); 2.28 dq, 2 H, J = 1.4, 3 × 7.3 (–CH=CHCH2–); 2.32
dt, 2 H, J = 0.5, 2 × 7.1 (–CH2C≡C–); 3.32 t, 2 H, J = 6.9 (–CH2OR); 5.43 dtt, 1 H, J = 2 × 1.4,
2 × 2.2, 10.7 (–CH=CH–); 5.81 dtt, 1 H, J = 1 × 1.4, 2 × 2.2, 10.7 (–CH=CH–). For C18H32
O
(264.5) calculated: 81.75% C, 12.20% H; foun d: 81.52% C, 12.33% H.
(4Z,6Z)-14-(tert-Butoxy)tetradeca-4,6-dien e (15)
Th e protected Z,Z-dien ol 15 (1.15 g, 80%) was prepared from en yn e 14 (1.45 g, 5.5 m m ol),
boran e–dim eth yl sulfide com plex (10 m ol l–1, 0.55 m l) an d cycloh exen e (0.90 g, 11.0 m m ol)
followin g th e procedure for th e preparation of com poun d 6. 1H NMR (CDCl3): 0.91 t, 3 H,
J = 7.3 (CH3CH2–); 1.18 s, 9 H (3 × CH3); 1.24–1.42 m , 8 H (4 × CH2); 1.41 m , 2 H
(CH3CH2–); 1.51 m , 2 H (–CH2CH2OR); 2.16 m , 4 H (2 × –CH=CHCH2–); 3.32 t, 2 H, J = 6.7
(–CH2OR); 5.39–5.48 m , 2 H (–CH=CH–CH=CH–); 6.22–6.29 m , 2 H (–CH=CH–CH=CH–).
For C18H34O (266.5) calculated: 81.12% C, 12.86% H; foun d: 81.01% C, 13.07% H.
(8Z,10Z)-Tetradeca-8,10-dien -1-ol (16)
Th e dien ol 16 (0.662 g, 79%) was obtain ed from com poun d 15 (1.07 g, 4.0 m m ol) followin g
the procedure for the deprotection of dienol 6. 1H NMR (CDCl3): 0.92 t, 3 H, J = 7.3 (CH3CH2–);
1.27–1.40 m , 8 H (4 × CH2); 1.41 m , 2 H (CH3CH2–); 1.56 m , 2 H (CH2CH2OH); 2.16 m , 4 H
(2 × –CH=CHCH2–); 3.64 t, 2 H, J = 6.6 (–CH2OH); 5.39–5.48 m , 2 H (–CH=CH–CH=CH–);
6.22–6.29 m , 2 H (–CH=CH–CH=CH–). For C14H26O (210.4) calculated: 79.94% C, 12.46% H;
foun d: 79.79% C, 12.31% H.
(8Z,10Z)-Tetradeca-8,10-dien al (1c)
Th e aldeh yde 1c (155 m g, 74%) was prepared from dien ol 16 (210 m g, 1.0 m m ol) an d PCC
(258 m g, 1.2 m m ol) followin g th e above described procedure for th e oxidation of dien ol 7
to dien al 1a. Isom eric purity 97% (GC). 1H NMR (CDCl3): 0.92 t, 3 H, J = 7.3 (CH3CH2–);
1.27–1.38 m , 6 H (3 × CH2); 1.41 m , 2 H (CH3CH2–); 1.63 m , 2 H (–CH2CH2CHO); 2.16 m , 4 H
(2 × –CH=CHCH2–); 2.43 dt, 2 H, J = 1.8, 2 × 6.4 (–CH2CHO); 5.39–5.48 m, 2 H (–CH=CH–CH=CH–);
6.22–6.28 m , 2 H (–CH=CH–CH=CH–); 9.75 t, 1 H, J = 1.8 (–CHO). EI-MS, m/z (rel.%): 39 (12),
41 (37), 54 (27), 55 (28), 67 (100), 68 (18), 79 (34), 80 (13), 81 (56), 82 (22), 91 (15), 93 (13),
95 (23), 96 (18), 98 (19), 109 (11), 208 (5, M+·). For C14H24O (208.3) calculated: 80.71% C,
11.61% H; foun d: 80.88% C, 11.62% H.
(Z)-9-Iodon on -8-en -1-ol (17)
Th e iodoalken ol 17 (1.31 g, 88%) was prepared from tert-butyl eth er 9 (1.80 g, 5.55 m m ol)
followin g th e above described stan dard deprotection procedure. 1H NMR (CDCl3): 1.29– 1.47 m ,
8 H (4 × CH2); 1.57 m , 2 H (–CH2CH2OH); 2.14 bdq, 2 H, J = 1.5, 3 × 7.5 (I–CH=CHCH2–);
3.64 t, 2 H, J = 6.6 (–CH2OH); 6.15–6.18 m , 2 H (I–CH=CH–). For C9H17IO (268.1) calcu-
lated: 40.31% C, 6.39% H, 47.33% I; foun d: 40.40% C, 6.11% H, 47.09% I.
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(8E,10Z)-Tetradeca-8,10-dienal
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(Z)-1-[tert-Butyl(dim eth yl)silyloxy]-9-iodon on -8-en e (18)
Th e silyl eth er 18 (1.54 g, 98%) was obtain ed from th e iodoalken ol 17 (1.10 g, 4.1 m m ol)
and tert-butyl(chloro)dim ethylsilane (650 m g, 4.3 m m ol) following the above described standard
silylation procedure. 1H NMR (CDCl3): 0.05 s, 6 H (2 × CH3); 0.89 s, 9 H (3 × CH3); 1.27–1.46 m ,
8 H (4 × CH2); 1.51 m , 2 H (–CH2CH2OR); 2.13 bdq, 2 H, J = 1.5, 3 × 7.1 (I–CH=CHCH2);
3.60 t, 2 H, J = 6.6 (–CH2OR); 6.14–6.18 m , 2 H (I–CH=CH–). For C15H31IOSi (382.4)
calculated: 47.11% C, 8.17% H, 33.19% I, 7.34% Si; found: 47.29% C, 8.28% H, 33.02% I, 7.46% Si.
(4E,6Z)-14-[tert-Butyl(dim eth yl)silyloxy]-tetradeca-4,6-dien e (19)
Com poun d 19 (390 m g, 65%) was prepared from vin yl iodide 18 (700 m g, 1.83 m m ol),
pen t-1-yn e (440 µl, 4.00 m m ol), DIBAH (1 M solution in h exan es; 2.0 m l), zin c ch loride (1 M
solution in THF; 2.0 m l), an d [Pd(Ph 3P)4] (300 m g, 0.26 m m ol) followin g th e above de-
scribed procedure for th e preparation of th e dien ic silyl eth er 15. 1H NMR (CDCl3): 0.05 s,
6 H (2 × CH3); 0.89 s, 9 H (3 × CH3); 0.90 t, 3 H, J = 7.2 (CH3CH2–); 1.29–1.41 m , 8 H (4 × CH2);
1.42 m, 2 H (CH3CH2–); 1.57 m, 2 H (–CH2CH2OR); 2.09 dq, 2 H, J = 1.6, 3 × 7.3 (–CH=CHCH2–);
2.16 dq, 2 H, J = 1.6, 3 × 7.3 (–CH2CH=CH–); 3.57 t, 2 H, J = 6.6 (–CH2OR); 5.29 bdt, 1 H, J =
2 × 7.3, 11.0 (–CH=CH–CH=CH–); 5.65 bdt, 1 H, J = 2 × 7.0, 15.0 (–CH=CH–CH=CH–); 5.95 ddt,
1 H, J = 0.8, 2 × 1.5, 11.0 (–CH=CH–CH=CH–); 6.30 ddq, 1 H, J = 3 × 1.5, 11, 15.0 (–CH=CH–CH=CH–).
For C20H40OSi (324.6) calculated: 74.00% C, 12.42% H, 8.65% Si; foun d: 74.11% C, 12.18% H,
8.50% Si.
(8Z,10E)-Tetradeca-8,10-dien -1-ol (20)
Th e Z,E-dien ol 20 (171 m g, 69%) was prepared from com poun d 19 (380 m g, 1.17 m m ol) fol-
lowin g th e above described stan dard deprotection procedure. 1H NMR (CDCl3): 0.91 t, 3 H, J =
7.0 (CH3CH2–); 1.29–1.43 m , 8 H (4 × CH2); 1.42 m , 2 H (CH3CH2–); 1.57 m , 2 H (–CH2CH2OH);
2.09 dq, 2 H, J = 1.6, 3 × 7.3 (–CH=CHCH2–); 2.16 dq, 2 H, J = 1.6, 3 × 7.3 (–CH2CH=CH–);
3.64 t, 2 H, J = 6.6 (–CH2OH); 5.29 bdt, 1 H, J = 2 × 7.3, 11.0 (–CH=CH–CH=CH–); 5.66 bdt, 1 H,
J = 2 × 7.1, 14.9 (–CH=CH–CH=CH–); 5.95 ddt, 1 H, J = 0.8, 2 × 1.5, 11.0 (–CH=CH–CH=CH–);
6.30 ddq, 1 H, J = 3 × 1.5, 11.0, 15.0 (–CH=CH–CH=CH–). For C14H26O (210.4) calculated:
79.94% C, 12.46% H; foun d: 80.14% C, 12.64% H.
(8Z,10E)-Tetradeca-8,10-dien al (1d )
Th e dien al 1d (67 m g, 64%) was obtain ed from dien ol 20 (105 m g, 0.50 m m ol) an d PCC
(130 m g, 0.6 m m ol) followin g th e above described procedure for th e preparation of com -
poun d 1a. Isom eric purity 96.5% (GC). 1H NMR (CDCl3): 0.91 t, 3 H, J = 7.0 (CH3CH2–);
1.26–1.38 m , 6 H (3 × CH2); 1.41 m , 2 H (CH3CH2–); 1.63 m , 2 H (–CH2CH2CHO); 2.42 dt,
2 H, J = 1.8, 2 × 7.3 (–CH2CHO); 2.16 dq, 4 H, J = 1.6, 3 × 7.3 (2 × –CH2CH=CH–); 5.40– 5.48 m ,
2 H (–CH=CH–CH=CH–); 6.22–6.28 m , 2 H (–CH=CH–CH=CH–); 9.76 t, 1 H, J = 1.8 (–CHO).
EI-MS, m/z (rel.%): 39 (11), 41 (34), 54 (25), 55 (28), 67 (100), 68 (18), 79 (34), 80 (13), 81
(51), 82 (21), 91 (16), 93 (14), 95 (25), 96 (19), 98 (18), 109 (14), 208 (9, M+• ). For C14H24
(208.3) calculated: 80.71% C, 11.61% H; foun d: 80.90% C, 11.50% H.
O
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In sects an d Bioassays
Cameraria ohridella adults were reared from pupae collected in Prague parks durin g autum n
1999. Em erged adults were sexed, an d two days old m ales14 were used for EAG experi-
m en ts15 with stan dard 1 n g doses of syn th esized com poun ds 1a–1d .
RESULTS AND DISCUSSION
Chemical Synthesis
Th e dien als 1a–1d were prepared usin g th e strategy sh own in Sch em e 1.
Th e key in term ediates for th e syn th esis, (E)-9-tert-butoxy-1-iodon on -1-en e
(4) an d (Z)-9-tert-butoxy-1-iodon on -1-en e (13), were prepared from 9-tert-
butoxyn on -1-yn e9 (3). Th e (E)-vin yl iodide 4 was syn th esized in h igh
stereoisom eric purity (98.2%, GC) usin g h ydroalum in ation 16 with diiso-
butylalum in ium h ydride (DIBAH) in h exan e followed by iodin ation of th e
form ed alken yl diisobutylalan e. For th e preparation of th e (Z)-vin yl iodide
13, h ydroboration of iodoalkyn e 12 with dicycloh exylboran e17 was used.
Th e m eth od for th e con struction of th e required carbon ch ain with a
con jugated dien e m oiety was differen t for th e 10Z an d 10E bran ch of th e
syn th etic sch em e. In th e first case, th e palladium -catalyzed cross-couplin g
of th e key in term ediate 4 (or 13) with pen t-1-yn e5,6 followed by cis-
h ydroboration with dicycloh exylboran e17 was used. In th e secon d on e, th e
palladium -catalyzed cross-couplin g reaction of th e vin yl iodide 4 (or 13)
with (E)-pen ten -1-yl diisobutylalan e7 (prepared by h ydroalum in ation of
pen t-1-yn e) directly providin g th e desired 8E,10E (or 8Z,10E) dien e system .
Th e sim plicity of th e design ed syn th etic strategy was h am pered by prob-
lem s with h ydroxy-protective groups. Th e tert-butyl group, wh ich was used
for protection of th e h ydroxy group of th e startin g m aterial 2, is gen erally
suitable as a protective group9 for th e m ajority of proposed syn th etic steps.
Th e tert-butyl group is also stable un der con dition s of h ydroalum in ation .
Un fortun ately, th e tert-butyl group sh owed to be un suitable for cross-
couplin g reaction s in th e presen ce of zin c ch loride (th e m odified Negish i
reaction 7). Th is stron g Lewis acid destroyed th e protected vin yl iodides 4
an d 13, wh ich resulted in virtually zero yields in th e above cross-couplin g
reaction . Th erefore, th e tert-butyl group was replaced with th e resistan t
tert-butyl(dim eth yl)silyl group (TBDMS) in th e vin yl iodides 9 an d 18.
In th e last steps of th e syn th esis, th e protected dien ols were deprotected
an d oxidized with pyridin ium ch loroch rom ate18 (PCC) to th e target com -
poun ds 1a–1d . Stereoisom eric purity of obtain ed dien als 1a–1d was h igh er
Collect. Czech. Chem. Commun. (Vol. 65) (2000)

(8E,10Z)-Tetradeca-8,10-dienal
521
Collect. Czech. Chem. Commun. (Vol. 65) (2000)

522
Hoskovec, Šaman, Svatoš:
th an 95% (GC). Overall yields of com poun ds 1a–1d were between 16 an d
26% based on th e startin g 7-brom oh eptan -1-ol.
EAG respon ses of 1a an d its geom etrical isom ers 1b–1d (Fig. 1) clearly
sh owed h igh selectivity of th e ph erom on e receptors on m ale an ten n a for
1a, wh ich was previously in depen den tly disclosed to be th e sex
ph erom on e3,4 of Cameraria ohridella. A sligh tly h igh er respon se of th e 1d
isom er is m ost likely due to th e sim ilarity of th e Z,E system to E,Z double
bon ds in 1a. Com plete dose-respon se curves of all th e isom ers will be pub-
lish ed elsewh ere.
125
100
75
FIG. 1
50
Relative EAG respon ses of C. ohridella m ales to
1 n g doses of (8E,10Z)-tetradeca-8,10-dien al
(1a) an d its isom ers (1b–1d ) expressed as per-
cen tages of th e EAG respon se to 1a. Each bar
is th e m ean of 3 replication s. Error bars repre-
sen t stan dard deviation of th e m ean
25
0
1a
1b
1c
1d
Financial support of the Municipal Council of the City of Prague, Department of Environment
(grant No. MHMP 45226/99) is gratefully acknowledged. We are thankful to Mr O. Blažek for con-
ducting EAG experiments.
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