FUROPYRIDINES .13. REACTION OF 2-METHYLFURO[2,3-B]PYRIDINES 2-METHYLFURO[3,2-B]PYRIDINES, 2-METHYLFURO[2,3-C]PYRIDINES AND 2-METHYLFURO[3,2-C]PYRIDINES WITH LITHIUM DIISOPROPYLAMIDE

Lithiation of 2-methylfuro[2,3-b]- 1a, -[2,3-c]- 1c and -[3,2-c]pyridi ne 1d with lithium diisopropylamide at -75-degrees and subsequent trea tment with deuterium chloride in deuterium oxide afforded 2-monodeuter iomethyl compounds 2a, 2c and 2d, while 2-methylfuro[3,2-b]pyridine 1b gave a mixture of 1b, 2b, 2-methyl-3-deuteriofuro[3,2-b]pyridine 2'b and 241-proynyl)pyridin-3-ol 5. The same reaction of la at - 40-degree s gave 3-(1,2-propadienyl)pyridin-2-ol 3 and 342-propynyl)pyridin-2-ol 4. Reaction of the lithio intermediates from 1a, 1c and Id with benza ldehyde, propionaldehyde and acetone afforded the corresponding alcoho l derivatives 6a, 6c, 6d, 7a, 7c, 7d, 8a, 8c and 8d in excellent yield ; while the reaction of lithio intermediate from 1b gave the expected alcohols 6b and 8b in lower yields accompanied by formation of 3-alkyl ated compounds 9, 11, 12 and compound 5. While reaction of the interme diates from 1a, 1b and Id with NN-dimethylacetamide yielded the 2-acet onyl compounds 13a, 13b and 13d in good yield, the same reaction of le did not give any acetylated product but recovery of the starting comp ound almost quantitatively.