204526-19-2Relevant articles and documents
Chiral synthons from carvone. Part 50. Enantiospecific approaches to both enantiomers of bicyclo[4.3.0]nonane-3,8-dione derivatives
Srikrishna,Reddy, T. Jagadeeswar
, p. 2040 - 2046 (2007/10/03)
Enantiospecific synthesis of both enantiomeric forms of bicyclo[4.3.0]nonane-3,8-dione derivatives has been described starting from (R)-carvone employing two different cyclopentannulation methodologies. Thus, in the first methodology, carveol (5) was converted into tricyclic ketone 4 employing a Claisen rearrangement and intramolecular diazo ketone cyclopropanation reactions. Degradation of the isopropenyl group followed by cyclopropane cleavage and cuprate addition generated the dione (-)-12a. Whereas, a Wacker mediated cyclopentannulation of (R)-carvone via the dione 15 furnished the, enone 17. Functional group manipulation including the degradation of isopropenyl group transformed the enone 17 into the dione (+)-12a, which on regioselective ketalisation generated the ketoketal (+)-2.
Total synthesis of (+)-ampullicin and (+)-isoampullicin: Two fungal metabolites with growth regulatory activity isolated from Ampulliferina sp. 27
Bermejo,Rico-Ferreira,Bamidele-Sanni,Garcia-Granda
, p. 8287 - 8292 (2007/10/03)
The total synthesis of the growth regulators (+)-ampullicin 1 and (+)-isoampullicin 2 from (R)-(-)-carvone 5 was accomplished by application of an 18-step sequence with 4.5% overall yield. The crucial step of the synthetic strategy lies on the internal displacement of tosylate 13 by means of the lactone enolate. In this way, access was opened to the tricyclic core present in these biologically active sesquiterpenic amides. A Horner-Emmons reaction between the carbaldehyde 16 and the phosphonate 22 led us to the stereoselective preparation of (+)-ampullicin 1. Standard transformation of 1 into the thermodynamically more stable geometric isomer (+)-isoampullicin 2 was trivial. The absolute configuration of both amides was established by X-ray analysis of a sample of synthetic (+)-isoampullicin 2.
Novel stereocontrolled synthesis of the tricyclic lactone (1R,3R, 6R,9S)-6,9-dimethyl-8-oxo-7-oxatricyclo[4.3.0.03,9]nonane
Rico, Rosario,Zapico, Julian,Bermejo, Francisco,Sanni, S. Bamidele,Garcia-Granda, Santiago
, p. 293 - 303 (2007/10/03)
The stereocontrolled synthesis of (1R,3R,6R,9S)-6,9-dimethyl-8-oxo-7-oxatricyclo[4.3.0.03,9]nonane 1 from (R)-(-)-carvone has been accomplished by application of a 13-step sequence with 12% overall yield. The absolute stereochemistry of the uns
Total synthesis of (-)-Ampullicin and (+)-lsoampullicin two growth regulators from Ampulliferina sp. no. 27
Rico, Rosario,Bermejo, Francisco
, p. 7889 - 7892 (2007/10/02)
The growth regulators (-)-Ampullicin (1) and (+)-isoampullicin (2) have been synthesized utilizing carbaldehyde (25) as the chiral source and N-tertbutoxycarbonyl-3-methyl-2-(trimethylsiloxy)pyrrole (33) as the five-carbon homologative reagent. The synthesis of (1) and (2) is discussed in the context of retrosynthetic analysis. Carbaldehyde (25), has been prepared from both enantiomers of carvone, either (7) or (9), by application of a 15-step sequence with 4.7% and 5.4% overall yields respectively.
