Yu. G. Chernov

Synthesis of Ecdysteroids and Related Compounds

Literature data published in 1998-2002 on the chemical synthesis of ecdysteroids and their structural analogs were reviewed.

Novel synthesis of (24R,6E)-24-ethylcholest-6-hydroxyimino-4-en-3-one, a steroidal oxime fromCinachyrella spp. sponges

Abstract(24R,6E)-24-ethylcholest-6-hydroxyimino-4-en-3-one (1), which was isolated previously fromCinachyrella spp. sponges, is synthesized in five steps from β-sitosterol in 30% overall yield.

Structure-Activity Relationship for Insecticidal Steroids. VI. 5,6-Disubstituted β-Sitosterols

The toxicity of steroids 1-14 for Colorado beetle (Leptinotarsa decemlineata Say.) larvae was studied by a contact-intestinal method. The most active are 3β,5α-dihydroxy-6-ketone 4a and 5α-hydroxy-3,6-diketone 8a.

13C NMR Spectra of 6-Hydroximinosteroids of the Stigmastane Series

Abstract13C NMR spectra were studied and signals of C atoms were assigned for 6-keto- and 6-hydroximinosteroids 1-10.

Structure-Activity Relationship of Insecticidal Steroids. VII. C-7-Oxidized β-Sitosterols and Stigmasterols

The toxicity of 7-substituted steroids 1-8 for Colorado beetle (Leptinotarsa decemlineata Say.) larvae was studied. The most active compound is 3-acetoxy-Δ5-7-ketone 2b.

Synthesis of α-chloropyridine-containing oximes of 3β,5-dihydroxy-6-ketosteroids

New derivatives of steroidal 6-ketoximes containing α-chloropyridine neonicotinoid groups characteristic of bioactive compounds were synthesized by formation of oximes of cholestane and stigmastane 3β,5-dihydroxy-6-ketosteroids with O-(2-chloropyridin-5-ylmethyl)hydroxylamine in the presence of zinc or tin(IV) chloride.

Synthesis of 7-oxo- and 7-hydroxy- derivatives of stigmasterol

The phytosteroids 3ß-hydroxy-(24S)-stigmast-5, 22E-dien-7-one and (24S)-stigmasta-5, 22E-diene-3\, 7ß-diol have been synthesized from stigmasterol.

Synthesis of (Z)- and (E)-3-(2-chloropyridin-5-ylmethyl) oximino-(22E,24R)-ergosta-4,7,22-trienes and their oxidative transformations

(Z)- and (E)-3-(2-chloropyridin-5-ylmethyl)oximino-(22E,24R)-ergosta-4,7,22-trienes (5–6) were synthesized by chemical transformation of ergosterol. Several oxidative transformations of them were studied. It was found that oxidation of these compounds by chromium(VI) oxide formed the corresponding O-substituted 3-ketoximes of the mycosteroid (22E,24R)-ergosta-4,7,22-trien-3,6-dione (7) and (8), which contained α-chloropyridine fragments characteristic of biologically active neonicotinoids. It was shown that oxidation of 5 and 6 by selenium dioxide occurred with formation of the corresponding 9α-hydroxy derivatives 9 and 10.

Intramolecular Hydrogen Bond in Steroid 5‐Hydroxy‐6‐Ketones and 5‐Hydroxy‐6‐Ketoximes of the Stigmastane Series

The intramolecular hydrogen bond in steroid 5‐hydroxy‐6‐ketones and 5‐hydroxy‐6‐ketoximes of the stigmastane series has been investigated by the method of IR spectroscopy. It is shown that 5β‐hydroxy groups in cis‐A/B‐steroids are linked by the intramolecular hydrogen bond with polar substituents at C3 and C6. These hydrogen bonds are lacking in corresponding trans‐A/B‐steroids. According to the IR spectra, intramolecular associates of polymer type are formed in 5‐hydroxy‐6‐hydroxyminosteroids.

Synthesis of the O-(2-chloropyridin-5-ylmethyl)oxime of 20-hydroxyecdysone

The new ecdysteroid derivative 20-hydroxyecdysone O-(2-chloropyridin-5-ylmethyl)oxime (3) was synthesized via the reaction of 20-hydroxyecdysone (1) and O-(2-chloropyridin-5-ylmethyl)hydroxylamine (2) in Py in the presence of SnCl4.