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Intramolecular diels-alder reactions. XI. Modal selectivity in the syntheses of some parent cyclolignan lactones |
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| Authors: | L H Klemm Vinh Tan Tran D R Olson |
| Abstract: | Ph(C2)CH2Cl and Ph(C2)'CO2Na where (C2) = -C=C- or trans-CH=CH-, (C2)' = -C=C- or cis-CH=CH-] reacted in refluxing dimethylformamide to yield unsaturated esters Ph(C2)'CO2-CH2(C2)Ph and/or their intramolecular Diels-Alder cyclization products (cyclolignan lactones). It was found that modal selectivity for cyclization in DMF sometimes varies from that found previously with acetic anhydride as solvent. Two new parent tetrahydrocyclolignan lactones were synthesized. |
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