Zur Synthese des Ecdysons IX. Mitteilung über Insektenhormone

Synthesis of A/B Ring Analogs of Territrem B and Evaluation of Their Biological Activities

“…Oxidation of aldehyde 15 with N-bromosuccinimide (NBS) under irradiation [9] gave the corresponding acyl bromide 18, which was treated directly with substituted phenols, thiophenols, or arylamines to afford the corresponding esters 19, thioesters 20, or amides 21 in 22.7 ± 75.2% yield (Scheme 2). Compounds 19 ± 21 were treated with Li 2 CO 3 in refluxing N,N-dimethylacetamide (DMAC) [10] for 30 min to afford the 2ene derivatives 22 ± 24 in 28.3 ± 83.9% yield. During the oxidation of 22 (R 1 R 3 H, R 2 H, 4'-Cl or 4'-NO 2 ) by CrO 3 in AcOH at 808, the yield of the corresponding target compounds 5 was not satisfactory (18 ± 29.4%) due to formation of the 1-en-3-one byproducts 25 by an unexpected radical rearrangement reaction.…”

EFFECTS OF ECDYSONES, JUVENILE HORMONE ANALOGS, AND 6-OXOOCTANOIC ACID ON THE DEVELOPMENT OF THE MOSQUITO, CULEX TARSALIS (DIPTERA: CULICIDAE)

“…The reduction in emergence after treatment of eggs with 50 p.p.m. of 22-isoecdysone was interesting because this compound has been considered to be inactive in other biological systems (Furlenmeier et al 1967;Judy 1969). Inhibition of metamorphosis in nymphs of Pyrrhocoris apterus L. and Oncopeltus fmciatus (Dallas) obtained from eggs treated with JH was reported by Riddiford ( 1 9 7 0~) .…”

Hexamethylphosphorous Triamide

“…It is worthy of note that the rates of these reactions are markedly enhanced by solvents of high polarity. (13) PhSMe + (R 2 N) 3 …”

“…In the synthesis of ecdysone from ergosterol, the ozonide product produced from (5) was reduced with (Me 2 N) 3 P under mild conditions to the aldehyde (6) without isomerization (eq 18). 13 The scope of this method has not been investigated. …”