Abstract When equimolar quantities of salicylaldehyde 2 and ethyl 3-amino-2-butenoate 3 or its constituents (ethyl 3-oxobutanoate and ammonia) were refluxed on a steam-bath for 6 hours with a trace of acetic acid, two products, a pentacyclic pyridine dilactone 4 and 3- acetyl coumarin 5, resulted in 15% and 45% yields, respectively. The structure of 4 was elucidated as 7-methyl [1] benzopyrano [4, 3-d][1] benzoxacino [4, 3-b]-pyridine-6, 16- ...