MODIFIED OZONOLYTIC SYNTHESIS
245
carbonyl compounds, and by modification of the carbon
skeleton in Z-unsaturated compounds [5, 6].
(capillary GLC data) was obtained. The IR and NMR
spectra of the product virtually coincide with those
described in [7].
This study was aimed at developing a modified
ozonolytic procedure for preparing 4Z-nonen-1-ol (4),
an intermediate for the synthesis of pheromones 2 and 3,
from the cyclic butadiene–isoprene codimer (5).
4Z-Nonen-1-ol (4). 80% hydrazine hydrate (1.88
g, 30.0 mmol) was added dropwise at 15°C to 1.56 g
(10 mmol) of 9-hydroxy-5Z-nonen-2-one (6) dissolved
in 10 mL of diethylene glycol. The mixture was stirred
for 3 h and allowed to stand for 16 h at room temperature.
Then, 2.8 g (50.0 mmol) of KОН was added, the mixture
was refluxed for 2 h, water and excess hydrazine hydrate
were distilled off by heating the mixture to 195°С, and
the mixture was heated at 195°C for an additional 4 h,
cooled to room temperature, diluted with 10 mL of
water, and extracted with diethyl ether (4 × 50 mL).
The combined organic layer was dried over Na2SO4 and
evaporated. The residue was chromatographed (SiO2,
hexane–Et2O, 3 : 1) to obtain 0.98 g (68%) of alkenol 4.
The IR and NMR spectra of the product were identical
to those described in [8].
EXPERIMENTAL
The IR spectra were recorded with an IR Prestige-21
device (Fourier Transform Spectrophotometer,
Shimadzu) from thin layers, and the NMR spectra,
with a Bruker AvanceIII 500 spectrometer [operating
frequencies 500.13 (1Н) and 125.76 MHz (13С)]
from solutions in CDCl3, with tetramethylsilane as
an internal reference. Gas–liquid chromatography
was performed with Chrom-5 [column length 1.2 m,
stationary phase 5% SE-30 on Chromaton N-AW-
DMCS (0.16–0.20 mm), working temperature
50–300°С] and Chrom-41 (column length 2.4 m,
stationary phase PEG-6000, working temperature
50–200°С) devices using helium as a carrier gas.
Thin-layer chromatography was performed on SiO2
of Sorbfil grade (Russia). Column chromatography
was performed on SiO2 (70–230 mesh, Lancaster, the
United Kingdom). The results of elemental analysis of
all the compounds agreed with the calculated data. The
ozonizer capacity was 40 mmol of О3 per hour.
RESULTS AND DISCUSSION
Success in catalysis of the oligomerization of the
simplest 1,3-dienes and alkenes by metal complexes
makes various unsaturated compounds of regular
structure, in particular, cyclic di- and trienes,
synthetically accessible. In turn, the subsequent chemo-
and regioselective cleavage of one of the multiple bonds
in such cyclopolyenes opens efficient synthetic routes to
acyclic α,ω-bifunctional unsaturated block intermediates
capable of further chemoselective transformations in
directional synthesis of biologically active compounds,
including low-molecular-mass insect bioregulators,
containing Z- or Е-alkene fragments [9].
9-Hydroxy-5Z-nonen-2-one (6). An ozone–oxygen
mixture was bubbled at 5°C through a solution of 1.95 g
(16.0 mmol) of cyclodiene 5 in 16 mL of distilled
cyclohexane, containing 1.85 mL (32.0 mmol) of glacial
acetic acid, until 14.4 mmol of ozone was taken up. Then,
the reaction mixture was purged with argon, the solvent
was separated from the precipitated peroxide product
by decantation, and the product was dissolved in 45 mL
of methylene chloride and added with stirring at 10°С
to a preliminarily prepared NaBH(OAc)3 suspension
[prepared by adding a solution of 11.9 g (198.0 mmol)
of glacial АсОН in 20 mL of CH2Cl2 to a suspension
of 2.50 g (66.0 mmol) of NaBH4 in 100 mL of CH2Cl2
and stirring for 2 h]. Then, the reaction mixture was
allowed to warm to room temperature, stirred for 3 h,
and cooled to 10°С, and a solution of 4.5 g of NaOH
in 100 mL of water was added. The organic layer was
separated, washed in succession with a saturated NH4Cl
solution and water, dried over Na2SO4, and evaporated.
1.92 g (85%) of keto alcohol 6 of 96% chemical purity
Efficient synthesis of a series of insect pheromones,
including pheromones 2 and 3, based on selective partial
ozonolysis of the cyclic isoprene–butadiene codimer,
1-methyl-1Z,5Z-cyclooctadiene (5) [10], was reported
previously [7]. Partial ozonolysis with 0.9 equiv of
ozone occurs with 90% selectivity across the trisubsti-
tuted double bond at 5°С in cyclohexane in the presence
of 4 equiv of methanol. The subsequent reduction with
hydrogen over Lindlar catalyst yields keto aldehyde 7.
Treatment of the latter with potassium triacetoxyboro-
hydride yields unsaturated hydroxy ketone 6 whose con-
version to the corresponding tosylhydrazone and subse-
quent reaction with sodium triacetoxyborohydride yields
4Z-nonen-1-ol (4). Its overall yield based on substrate 5
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 92 No. 2 2019