Tricyclic sesquiterpenes and further diterpenes from Espeletiopsis species
作者:F. Bohlmann、H. Suding、J. Cuatrecasas、H. Robinson、R.M. King
DOI:10.1016/s0031-9422(00)91035-5
日期:1980.1
Abstract The investigation of five Espeletiopsis and two Coespeletia species afforded, in addition to numerous known compounds, two new kaurene derivatives 19-acetoxy-ent-kaurene and 17-oxo-ent-kaur- 15-en-19-oic acid, as well as two new tricyclicsesquiterpenes, one being the previously reported oxidation product of copaborneol and the second one the 5-oxo derivative of silphiperfol-6-ene. The structures
Expeditious Syntheses of (±)-5-Oxosilphiperfol-6-ene and (±)-Silphiperfol-6-ene
作者:T. Jagadeeswar Reddy、Viresh H. Rawal
DOI:10.1021/ol006292q
日期:2000.8.1
[reaction: see text]Stereocontrolled syntheses of 5-oxosilphiperfol-6-ene (1) and silphiperfol-6-ene (2) have been accomplished in four and five steps, with overall yields of 32% and 26%, respectively, from 1-acetyl-3-methylcylopentene. The strategy features two pivotal reactions: (a) a Diels-Alder reaction between 1,3-dimethylcyclopentadiene and 1-acetyl-3-methylcyclopentene, which proceeds with remarkable
Novel rearrangement of 5,6-disubstituted bicyclo[4.2.0]octan-2-ones with aluminum chloride. Application to total synthesis of (.+-.)-5-oxosilphiperfol-6-ene and (.+-.)-silphiperfol-6-ene