Benzofurans 2,3-dihydro-, 5-hydroxy- from

The synthesis of the (i) 4-hydroxy-6-methoxytetrahydrofuro[2,3-6]-benzofuran ring (116), a degradation product of natural substances of the sterigmatocystin series, is similar,318 as is the synthesis of the dihydro derivative (117) from the o-acetylated acetaldehyde (118), a nonisolated intermediate which is ring-closed to 119 and then heated in toluene to give 117. The last is the starting point for the synthesis of aflatoxin M4 (49).153... 

V. Enamines. Reactions of the enamines from condensation of piperidine or morpholine with an aldehyde with p-benzoquinone gives 2,3-dihydro-5-hydroxy-2-piperidino(or morpholino)benzofurans (146),... 

Formation of the methylcarbamate of 2,3-dihydro-2,2- dimethyl-4-hydroxy benzofuran in 57% yield has been reported from the N-methylamido derivative of saccharin through nucleophilic substitution by the addition of triethylamine in aqueous acetone (1 2) at ambient temperature over 2 hours (ref.29). 

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