An efficient route to 1-formyl-1,2-dihydroquinolines 6 is described based on the BF3-catalyzed cyclization of o-(1-hydroxy-2-alkenyl)phenyl isocyanides 4, which can be prepared feasibly by the reaction of N-(o-acylphenyl)formamides 1 with alkenylmagnesium bromides 2 followed by treatment of the resulting hydroxy formamides 3 with phosphorous oxychloride.

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A new method for the preparation of 3-isochromanone derivatives is reported. The method consists of the ethoxycarbonylation of o-acylbenzyllithiums with ethyl chloroformate and the subsequent NaBH4 reduction of the resulting o-acylphenylacetic acid derivatives.

The reactions of sulfoxides with magnesium amides generated in situ from the reaction of ethylmagnesium bromide and secondary amines, such as diisopropylamine (DIPA) or 2,2,6,6-tetramethylpiperidine (TMP) in diethyl ether, were examined. Diaryl sulfoxides were heated with the diisopropylaminomagnesium reagent in diethyl ether to give the corresponding diaryl sulfides in 42—52% yields. Sulfoxides bearing hydrogens at the α-positon only (RSOCH2R1) reacted with the tetramethylpiperidinomagnesium reagent at room temperature to produce the corresponding dithioacetals (RSCHR1SR) in 47—86% yields. The treatment of sulfoxides bearing hydrogens both at the α- and β-positions (RSOCHR1CHR2R3) with the magnesium amides at room temperature afforded the corresponding vinyl sulfides (RSCR1=CR2R3) in 52—72% yields accompanying 2.3—27% yields of the corresponding dithioacetals. The pathways leading to the products involving the formation of the sulfur-stabilized carbonium ion intermediates are discussed.