S. R. Afon’kina

7,8-dihydro analogs of ecdysteroids

Reactions of 20-hydroxyecdysone, its diacetonide, and 24,25(25,26)-anhydro derivative with lithium tetrahydridoaluminate gave the corresponding 6α- and 6β-epimeric alcohols and 7,8-dihydro analogs.

Synthesis of 20-hydroxyecdysone oxime, its diacetonide, and their 14,15-anhydro derivatives

Abstract20-Hydroxyecdysone oxime, its diacetonide, and the corresponding 14,15-anhydro derivatives were synthesized. Conditions were found for the preparation of the Z-and E-oximes, and their characteristics 1H and 13C NMR parameters were determined.

20-hydroxyecdysone oximes and their rearrangement into lactams

Abstract(E)-Oximes derived from 20-hydroxyecdysone diacetonides and 7,8-dihydro analog were converted into the corresponding lactams (6-oxo-5a-aza-5a-homo derivatives) via Beckmann rearrangement. 14,15-Anhydro-20-hydroxyecdysone (Z)-oxime under analogous conditions (reaction with p-toluenesulfonyl chloride in acetone in the presence of Na2CO3) gave rise to 20-hydroxyecdisone 20,22-acetonide (Z)-O-tosyloxime which did not undergo Beckmann rearrangement.

Transformation of ω-anhydro-20-hydroxyecdysone diacetonide into 7,8α-dihydroponasterone a and its acetonides

Abstract7,8α-Dihydroponasterone A and its mono- and diacetonides were synthesized via catalytic hydrogenation of ω-anhydro-20-hydroxyecdysone 2,3: 20,22-diacetonide over Pd/C in methanol in the presence of sodium methoxide.

Analogs of ecdysteroids with a tetrasubstituted Δ8,14-bond

By hydrogenation of (20R,22R)-6α,14α,25-trihydroxy-and (20R,22R)-6β,14α,25-trihydroxy-2,3:20,22-bis(isopropylidenedioxy)-5α-cholest-7-enes on a catalyst (Raney nickel) the corresponding (5α,6α)-and (5β,6β)-epimers of previously unknown Δ8,14-6-hydroxy derivatives of ecdysteroids were synthesized.

9α-hydroxylation of 25-fluoroponasterone a diacetonide in lithium-ammonia solution

Abstract25-Fluoroponasterone A diacetonide reacted with lithium in liquid ammonia to give 25-fluoro-9α,20-dihydroxyecdysone diacetonide whose hydrolysis afforded 25-fluoro-9α,20-dihydroxyecdysone 20,22-acetonide. Nonfluorinated analog of the latter was isolated previously from Silene italica ssp. nemoralis.

Cyclocondensation of lower aliphatic aldehydes with arylamines and cyclopentadiene

Three-component condensation of lower aliphatic aldehydes (C1-C3) with arylamines and cyclopentadiene (the Povarov reaction) gave 3a,4,5,9b-tetrahydro-3H-cyclopenta[c]-quinolines. Ozonization of their N-trifluoroacetyl derivatives afforded the corresponding ozonides. Cyclocondensation of 4-fluoroaniline with formaldehyde and cyclopentadiene gave earlier unknown 2-fluoro-3b,6,6a,7,9,9a,10,12a-octahydrobenzo[i,j]dicyclopenta[b,g]quinolizine.