Azulenes, labdanes and a furocurcumene from Ixiolaena leptolepis

A Synthesis of (±)-Furoixiolal

“…Furoixiolal, a sesquiterpenoid furanoaldehyde, was isolated from the aerial parts of Ixiolaea leptolepis. It has been assigned structure 1 on the basis of spectroscopic studies (1). In the present paper we report an unambiguous synthesis of furoixiolal [1] to confirm its structure and to have the natural product in reasonable amount for studying its conversion to other /i-curcumene type sesquiterpenoids.…”

“…It has been assigned structure 1 on the basis of spectroscopic studies (1). In the present paper we report an unambiguous synthesis of furoixiolal [1] to confirm its structure and to have the natural product in reasonable amount for studying its conversion to other /i-curcumene type sesquiterpenoids. The synthesis is delineated in Scheme 1.…”

“…4-Formyl-2-(2'-j?-tolylpropyl)furan (furoixiolal) [1],-To a suspension ofLAH (0.19 g, 0.005 mol) inEt20(15 ml) was added dropwise ester 7 (1.35 g, 0.005 mol) in Et20 (10 ml). The mixture was refluxed for 6 h and then cooled to 0°.…”

An Erratum

“…[39] The extract of the aerial parts of Ixiolaena leptolepis yielded two labdane HDs (6) and (7). [40] A clerodane HD, 2βhydroperoxykolavelool (8) was obtained from the ethanol extract of the stems of Aristolochia chamissonis. [41] Aster spathulifolium from the Far East provided 7α-hydroperoxymanool (9) which showed moderate cytotoxicity against human cancer cells, [42] and similar type DH (8S)-hydroperoxy-(13S)-hydroxy-9(11),14-labdadiene (10) was found from Jungermannia infuscua.…”

Heterocyclic terpenes: linear furano- and pyrroloterpenoids

“…56 The structure 74 has been assigned to a furanosesquiterpenoid obtained from the extract of the aerial parts of Ixiolaena leptolepis. 57 Two new furanosesquiterpene alcohols, pelseneeriol 1 75 and pelseneeriol 2 76, have been isolated from the porostome nudibranch Doriopsilla pelseneeri, collected off the Portuguese coast (Atlantic Ocean). 58 An approach known to give regiospecific and stereospecific reactions has been applied to the first enantioselective synthesis of the natural (−)microcionin 2 77, an example of a molecule containing a trans relationship between the methyl groups.…”