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The 10E,12Z- and 10E,12E- isomers of hexadecadien-1-ol and of hexadeca-10E,12Z-dienal — components of the sex pheromone of the silkworm mothBombyx mori — have been synthesized from the readily available octa-2E,7-dien-1-ol.

Non-6E-en-l-ol, dodec-3E-en-l-yl acetate, and dodeca-7E, 9Z-dien-l-yl acetate, which are components of sex pheromomes of insects of the orderLepidoptera, have been synthesized from the readily accessible isopropyl nona-3E,8-dienoate.

A new route, based on the partial ozonolysis of ω-acetyl derivatives of alk-1-en-4-ynes, is proposed for the synthesis of 11RS-hydroxydodec-3Z-enoic acid, the cyclization of which gives dodec-3Z-en-11RS-olide (ferrulactone II) — a racemic analogue of one of the macrolide components of the aggregation pheromone of the rust-red grain beetle.

A new approach to the synthesis of 11RS-hydroxy- and 12-hydroxydodec-3Z-enoic acids has been developed with the use, in one of the key stages, of the partial ozonolysis of the acetates of the corresponding methylene-separated enynic alcohols.

10-Hvdroxy-4,8-dimethyldeca-4E,8E-dienoic acid and racemic 4,8-dimethyldecanal (components of beetle pheromones) have been synthesized from geranyl acetate.

Schemes for the synthesis of long-chain 1,5-dimethyl-branched pheromones (7,11-dimethyloctadecane, 15,19-dimethyltritriacontane, and 2-acetoxy-3,7-dimethylpentadecane) from the product of the allyl oxidation of geranyl acetate (8-acetoxy-2,6-dimethylocta-2E,6E-dien-1-ol) have been developed.

From cyclohexene and caproaldehyde, using ozonolysis and the Knoevenagel reaction, we have synthesized hexadeca-7Z,11E-dien-l-yl acetate — the sex pheromone ofSitotroga cerealella and a component of the sex pheromone ofPectinophora gossypiella.

Tetradeca-9Z,12E-dien-l-yl acetate, a sex pheromone of the Indian meal mothPlodia interpunctella has been synthesized from the readily available product of the hydrodimerization of butadiene — octa-1,7-diene.

The selective ozonolysis of pentadec-1-en-12-yne and heptadec-1-en-12-yne, synthesized from the readily available undecylenic acid, has given tetradec- and hexadec-11-yn-1-ols — acetylenic precursors of a number of pheromones of insects of the order Lepidoptera.

A synthesis of hexadec-9Z-enal — a component of the sex pheromone of the cotton boll-wormHeliothis armigera (Hubner) — based on cyclooctene (I) is proposed. Through a solution of 22 g of (I), 250 ml of cyclohexane, and 40 ml of MeOH is passed (at 5°C) 0.2 M O3/O2, the solution is decanted off, and the precipitated ozonide is dissolved in 200 ml of MeOH and is reduced with 19 g of NaBH4 (40°C) with the isolation, after the usual working up, of 23.4 g of octane-1,8-diol (II). From 0.5 mole of (II) and 0.6 mole of 45% HBr 8-bromooctan-1-ol (III) is obtained and this is converted into 1-(2-THPL)oxy)-8-bromooctane (IV). The condensation of (IV) with oct-1-yne (Ar, LiNH2, HMPTA, 10°C, 1 h, and then 55°C, 10 h) leads to 1-(2-THPL-oxy)hexadec-9-yne (V) the hydrolysis of which (MeOH, H2O, p-TsOH, 20°C for 20 h) yields hexadec-9-yn-ol (VI). The reduction of (VI) (Et2O, iso-BuMgBr, Cp2TiCl2, 0°C, 15 min, then 20°C, 1 h) yieldshexadec-9Z-en-l-ol (VII). The oxidation of (VII) (PyHCrO 3 + Cl−, CH2Cl2, 20°C, 2 h) gives hexadex-9Z-enal (VIII). Characteristics of the compounds (yield (%), n D 20 (25): (II) − 80, mp 61–62°C; (III) − 75, 1.4807; (IV) − 99, —; (V) − 52, 1,4650; (VI) − 85, 1.4657; (VII) − 99, 1.4650; (VIII) − 98, 1.4600. Characteristics of the IR and PMR spectra of compounds (V–VII) are given.

A new effective route to the synthesis of 7-oxooctanal has been found which is based on the ozonolysis of the tetrahydropyran-2-yl ether of 7-methyloct-7-en-l-ol — the product of the coupling of the readily available methallyl chloride and the Grignard reagent from the corresponding ether of 5-bromopentan-l-ol. From the 7-oxooctanal has been obtained 9-oxodec-2E-enoic acid — a pheromone of the honeybeeApis melliferana.