Total Synthesis of (+)-Ampullicin and (+)-Isoampullicin: Two Fungal Metabolites with Growth Regulatory Activity Isolated from Ampulliferina Sp. 27
摘要:
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 I 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.
Total Synthesis of (+)-Ampullicin and (+)-Isoampullicin: Two Fungal Metabolites with Growth Regulatory Activity Isolated from Ampulliferina Sp. 27
摘要:
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 I 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.
Stereoselective preparation of (5E)- and (5Z)-5-benzylidene-3-methyl-3-pyrrolin-2-ones. Application to the synthesis of ampullicine and isoampullicine
作者:Rosario Rico、Francisco Bermejo
DOI:10.1016/0040-4039(96)01232-4
日期:1996.8
The application of N-Boc-5-phosphoranylidene- and N-Boc-5-diethylphosphonate-3-methyl-3-pyrrolin-2-ones to the stereoselective synthesis of (5E)- and (5Z)-3-methyl-5-benzylidene-3-pyrrolin-2-ones is examined. The stereoselective synthesis of the growth regulators Ampullicin and Isoampullicin by using both Wittig intermediates has also been achieved.
Synthesis of azaspiro[4.5]decane systems by oxidative cyclization of olefinic precursors
作者:María J. Martín-López、Francisco Bermejo
DOI:10.1016/s0040-4020(98)00746-7
日期:1998.10
The synthesis of 6-benzyloxycarbonyl-1-oxa-6-azaspiro[4.5]decan-2-one (17) and 6-benzyloxycarbonyl-1,6-diazaspiro[4.5]decan-2-one (18) from the D,L-pipecolic acid derivative 10, is described. The synthesis of (±)-6-benzyl-3-methyl-1,6-diazaspiro[4.5]dec-3-ene-2,7-dione (29), the spiro structural unit of (±)-pandamarine (8) has been achieved by oxidative cylization of the (Z) and (E) isomers of 5-(N-