The synthesis of 1,8-disubstituted 10,11-dihydrodibenz[b,f]oxepin-10-ones. analogues of anaesthetic steroids

Abstract

1,8-Disubstituted 10,11-dihydrodibenz[b,f]oxepin-10-ones 4a, b and 5a, b have been synthesised as analogues of steroid anaesthetics 2 and 3 respectively. The novel partial Ullmann reaction between methyl 2,6-dichlorophenylacetate 7 and 4-substituted phenols 8e, b gave diphenyl ether derivatives 9a, b. The latter were then hydrolysed and cyclodehydrated to give 1,8-disubstituted 10,11-dihydrodibenz[b,f] oxepin-10-ones 11a, b which underwent selective functional group transformations to give 4a, 5a and 4b, 5b respectively. Lithium borohydride reduction of the ester 13b to the benzyl alcohol 14b proceeded without reduction of the enol ether function.