There are provided benzopyrans of formula I,
wherein an adjacent pair of R 5 , Re, R 7 and R 8 represent the chain -X-CR 12 R 13 -CR 14 R 15 -Y- in which the chain is substituted by -A 1 E 1 ,
X represents CR 10 R 11 or a single bond, Y represents 0, S, NR 20 or CR 16 R 17 , and
(a) R 14 and R 20 together form a single bond and optionally R 10 and R 12 together form a single bond, or (b) R 12 and R 14 together form a single bond, or (c) Rio, R 12 and R 14 each represent hydrogen; and the remainder of Rio, R 11 , R 12 , R 13 , R 14 , R 15 , R 16 and R 17 , which may be the same or different, independently represent hydrogen, alkyl, NR 21 COR 22 , CN or C n H x F (2+1-x) ; in addition, a a geminal pair of Rio, R 11 , R 12 , R 13 , R 14 , R 15 , R 16 and R 17 together with the carbon atoms to which they are attached, may represent C=O or C=N-OR 23 ; also a vicinal pair of R 11 , R 13 , R 15 and R 17 , may form the chain -CH =CH-CH=CH- which is substituted by A 1 E 1 ; A and A 1 , which may be the same or different, represent a single bond, (CH 2 ) m or arylene, n represents an integer from 1 to 10 inclusive, x represents 0 or an integer from 1 to 2n inclusive, m represents an integer from 1 to 10 inclusive, when R 20 does not form a single bond with R 14 , R 20 may represent hydrogen, alkyl, aryl or alkyl substituted by aryl, R 21 , R 22 and R 23 , which may be the same or different, independently represent hydrogen, alkyl or aryl; the remainder of R 5 , R 6 , R 7 and R 8 , which may be the same or different, each independently represent hydrogen, hydroxy, alkoxy, amino, halogen, nitro, cyano, alkyl, aryl or alkyl substituted by aryl, E and E 1 , which may be the same or different, independently represent -COOH, or 5H-tetrazolyl, with certain provisos defined herein, and pharmaceutically acceptable derivatives thereof. There are also decribed processes to the compounds of formula I and pharmaceutical, e.g. anti-asthma, compositions containing them.