An approach to the synthesis of pederin

Abstract

-Pederin, the vesicant component found in the haemolymph of many species of the staphylinid beetle of the genus Paederus, is a powerful inhibitor of protein synthesis in eucaryotic cells. Hith its nine chiral centers and its unusual functfonality, it is also the most complex, non-proteinaceous insect defensive compound known. This paper describes our progress toward a total synthesis of this fascinating natural product.Nature' s use of organic chemieals for .defensive purposes is one of the most intriguing areas of "applied organic chemistry". Arthropods are particularly skillful chemists (1); their defensive agents range from the elegant simplicity of single carbon compounds such as hydrogen cyanide and formic acid, through a variety of simple aliphatic compounds, to quinones, terpenes and "alkaloids" (2). Probably the most complex, non-proteinaceous defensive compound so far characterized is produced by staphylinid beetles of the genus Paederus (known in East Africa as the "Nairobi Eye Fly"). The dramatic vesicant properties of these be~tles were first described in 1912 (3), although the isolation of pederin (the haemolymph component responsible for the vesicant effect) in crystalline form and the demonstration that pederin is different from the notorious insect product cantharidin (another vesicant of considerable interest) are more recent (4).Extensive chemical and spectral studies were carried out on pederin in Italy (5) and in Japan (6), culminating in X-ray crystallographic studies (7) which resulted in tae determination of both its structure and absolute stereochemistry.

Using ring-opening reactions of oxabicyclic compounds as a strategy in organic synthesis

“…Silyl protection gave alcohol 125 and reduction transformed the thioether linkage into the vicinal cis dimethyl groups found in (+)-nemorensic acid [137]. Previous synthetic studies that have employed ozonolysis as a means for cleaving oxabicyclic substrates include Meinwald's studies toward pederin [ 138], Just's synthesis of showdowmycin [139], Masamune's synthesis of avenaciolide [140], and Ohno's asymmetric syntheses of (+)-showdowmycin, (-)-cordycepin C, and (-)-6-azapseudouridine [ 141 a].…”

New chemical and stereochemical applications of organoiron complexes

“…(±)Nonactic acid 241 [ 409 ] was synthesized [ 424 ] through 239 and 240 [ 409 ]. The ketones 239 [ 409 ] served for the construction of the right-hand block of (±)-pederin 242 [ 425 ]. Preparation of a thromboxane A 1 analog 243 [ 426 ] was accomplished by starting from 215 [ 409 ] ( Scheme 42 ).…”

Total synthesis of dl-pentalenolactone

“…Apparently dialdehyde 45 is extensively hydrated in aqueous medium. 22 Several attempts were made to achieve aldol cyclization of the unstable keto dialdehyde 45. The only conditions where some measure of success was attained involved heating 45 with piperidine in acetic acid.…”