Methyl 3-oxovalerate → Methyl 1,8-diethyl-1,3,4,9-tetrahydropyrano(3,4-b)indole-1-acetate

Participants

Reaction Conditions

Reaction Steps

To a solution of 7-ethyltryptophol (12.0 g) in 1-butanolic hydrogen chloride (5% w/v, 100.0 ml), methyl 3-oxopentanoate (9.1 g) was added in one lot, at 25° C. The reaction mixture was stirred at 25-30° C. for 7 hours. The reaction mixture was extracted with hexane (100.0 ml). Hexane was concentrated to about 20 ml and methanol (10 ml) was added. The product was filtered, washed with methanol and dried to afford the titled compound (14.7 g, 79%), m.p. 128-130° C.; purity: 96.2%.

Provenance & Evidence