Erythrodiene: A new spirobicyclic sesquiterpene of a rare skeletal class from the caribbean gorgonian coral Erythropodium caribaeorum
摘要:
Erythrodiene (1), a new sesquiterpene hydrocarbon of a rare structural class, has been isolated from the encrusting Caribbean gorgonian coral Erythropodium caribaeorum. The structure of the new compound was assigned on the basis of spectral studies and through an X-ray analysis of a reduced ozonolysis product, the diol 2.
A stereoselective total synthesis of (±)-erythrodiene
摘要:
Erythrodiene, a unique spirobicyclic sesquiterpene hydrocarbon from the Caribbean gorgonian cord Erythropodium caribaeorum, has been synthesized from 4-isopropylcyclohexanol in 8-steps and approximately 16% overall yield. The synthesis features a stereoselective intramolecular carbomercuration reaction as the key step.
An efficient synthesis of spirobicyclic sesquiterpenes, (±)-spirojatamol 1 and (±)-erythrodiene 2, using an intramolecular 1,3-dipolar cycloaddition as the pivotal step is described.
achieved from cyclobutone and isobutyraldehyde through an 11-step synthetic route. During the work, a tandem Castro-Stephens coupling/1, 3-acyloxy shift/cyclization/semipinacolrearrangement sequence, which was developed recently by the same group, was used as the key step to build the crucial spirocyclic intermediate 5b.
Two spirobicyclic sesquiterpenoids, (-)-erythrodiene (1) and (+)-7-epispirojatamol (30),were synthesized in enantiomerically pure form via an intramolecular allylzincation process. The allylzinc species were formed in the presence of Et,Zn via transmetallation of a catalytically generated allylpalladium intermediate. Several Pd catalysts were tested for this transformation, and [Pd(OAc)(2)/Bu3P(1 equiv.) was found to be, by far, the most effective. Whereas the preparation of 1 involved allylzincation of a tethered terminal olefin. 30 was formed via a novel intramolecular allylzincation of a methyl ketone. Both reactions showed the same stereochemical preference. yielding the spirobicyclic products in 95:5 and 4:1 diastereoisomer ratios, respectively.
A stereoselective total synthesis of (±)-erythrodiene
作者:He Huang、Craig J. Forsyth
DOI:10.1016/s0040-4039(00)61502-2
日期:1993.12
Erythrodiene, a unique spirobicyclic sesquiterpene hydrocarbon from the Caribbean gorgonian cord Erythropodium caribaeorum, has been synthesized from 4-isopropylcyclohexanol in 8-steps and approximately 16% overall yield. The synthesis features a stereoselective intramolecular carbomercuration reaction as the key step.
Erythrodiene: A new spirobicyclic sesquiterpene of a rare skeletal class from the caribbean gorgonian coral Erythropodium caribaeorum
Erythrodiene (1), a new sesquiterpene hydrocarbon of a rare structural class, has been isolated from the encrusting Caribbean gorgonian coral Erythropodium caribaeorum. The structure of the new compound was assigned on the basis of spectral studies and through an X-ray analysis of a reduced ozonolysis product, the diol 2.