Pallescensins are a group of furanosesquiterpenoids isolated from the marine sponge Disidea pallescens by Cimino et al.1 The common feature of these terpenoids is that they all contain a furan moiety; however they have carbon skeletons of varying complexity. Among the pallescensins, pallescensin B 1 presents the most complex architecture, with a unique bicyclo[4.2.2]decane system fused to a fur...

We describe an isomerization-alternating ROMP protocol that gives linear copolymers with rigorous sequence alternation. Bicyclo[4.2.0]oct-7-ene-7-carboxamides of primary amines are isomerized in the presence of (3-BrPyr)2Cl2(H2IMes)Ru=CHPh to the corresponding bicyclo[4.2.0]oct-1(8)-ene-8-carboxamides in which the olefinic bond is tetrasubstituted. The isomerized amides undergo alternating ring...

We have optimized a synthetic approach to (±)-Ferrugine in 8 steps starting from 5-aminocyclohept-1-ene and using the Brønsted acid-catalyzed pseudotransannular ring-opening of epoxide derived this cycloheptene as key step for construction 8-azabicyclo[3.2.1]octane central core. While attempting enantioselective synthesis natural product enantiopure 2-hydroxy-8-azabicyclo[3.2.1]octane we found ...

New and simple protocols are described for the conversion of the enzymatically-derived and enantiomerically pure cis-1,2-dihydrocatechol (X = I) and its 6-methylated derivative into either antipodal form of compounds embodying the tricyclic frameworks of terpenoids . Key steps include intramolecular Diels-Alder (IMDA) and (in some cases) singlet or triplet-based photochemical processes.

Cyclooctatetraene dianion (I) reacts as a 1,2and a 1 ,4-dicarbanionic reagent with various acyl halides. Thus I and acetyl chloride give 3,5,7,9-dodecatetraene-2,1l-dione (111), syn-9-acetoxy-9-methylbicyclo[4.2.1]nonatriene (V), syn-9-hydroxy-9-methylbicyclo[4.2.l]nonatriene (IV), and syn-9-acetoxy-9-methylbicyclo[6.1 .O]nonatriene (VI). Benzoyl chloride and I yield truns,cis,cis,trans-l ,lO-d...

IR and Raman spectra and phase transitions have been studied on various salts of azabicyclo[2.2.2]octane (ABCO) and l,4-diazabicyclo[2.2.2]octane (DABCO) which forms with simple strong acids adducts of 2 : 1, 1 : 1 and 1 : 2 composition. Only 2 : 1 DABCO adducts form homoconjugated cations containing [NH · · · H]+ hy. drogen bonds close to symmetrical ones, showing broad absorption in the low f...

The bicycloannulation reaction between cyclohexenone and indolyl enamines yields trans-3-(cyclic amino)-2-(3'-indolyl)bicyclo[2.2.2]octan-5-ones, and these adducts are conformationally restricted analogues of indolylethylamine (tryptamine) which exhibit structure-dependent affinity for the serotonin 5HT2 and 5HT1a receptors. The stereochemistry of the isomeric endo and exo adducts obtained is a...