Abstract
The unsubstituted pyrylium nucleus is shown to undergo reaction with cuprate or secondary Grignard organometallic reagents to give intermediate 4-substituted pyrans which are converted into the corresponding 4-substituted pyrylium salts (7 examples) in fair to good overall yield. The synthetic utility of the 4-substituted pyrylium heterocycles is demonstrated by their reaction with organolithium reagents to give 3,5-disubstituted dienals in a highly stereospecific manner (7 examples) via electrocyclic ring opening of the intermediate 2-substituted pyrans.
Original language | English |
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Pages (from-to) | 1083-1089 |
Number of pages | 7 |
Journal | JOURNAL OF HETEROCYCLIC CHEMISTRY |
Volume | 33 |
Issue number | 4 |
Publication status | Published - 1996 |
Keywords
- CONVENIENT METHOD
- STEREOSELECTIVE SYNTHESIS
- REGIOSELECTIVE SYNTHESIS
- REAGENTS
- 4-ALKYL(ARYL)PYRIDINES