1- Methylquinolinium salt, reduction with

Complex hydride reduction (NaBH4 or LiAlHJ of 1-methylquinolinium ions proceeds analogously to 1,2-dihydro compounds (e.g. 333). 1-Methyl- and 1-acylisoquinolinium ions (the latter with Bu3SnH (88CL913)) give the corresponding 1,2-dihydro compounds (334). Borohydride reduces pyrylium salts to mixtures of 2H- and 4/7-pyrans the former immediately ring opens to form the dienone (Scheme 33). 

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