Studies on the synthesis of heterocyclic compounds. XV. Preparation of a new series of macrocycles with the diglycolyl moiety

A new series of macrocycles containing the diglycolyl moiety have been prepared. The compounds prepared were: 7,9,18,20‐tetrahydrodibenzo[ b,k ][1,4,7,10,13,16]hexaoxacyclooctadecin‐6,10,17,21‐tetraone ( 1 ), 1,4,7,10,13,16‐hexaoxacyclooctadecane‐2,6,11,15‐tetraone ( 2 ), 8,7,17,18‐tetramethyl‐1,4,7,10,13,16‐hexaoxa‐cyclooctadecane‐2,6,11,15‐tetraone ( 3 ) and 2,5,8,15,18,21 ‐hexaoxatricyclo[20,4,0,0 9.14 ]hexacosan‐3,7,16,20‐tetraone ( 4 ). The compound 4 has been isolated in the four diastereoisomers: trans‐syn‐trans 4a , trans‐anti‐trans 4b , cis‐syn‐cis 4c and cis‐anti‐cis 4d .