A New synthesis of dimethyldihydropyrene-2, 7-quinone and the study of its reactions in the synthesis of novel aromatic and other interesting molecules
Date
1994
Authors
Jin, Xin
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
A new synthesis of trans-10b,10c-dimethyl-10b,10c-dihydropyrene-2,7-quinone, 17, was developed via the oxidation of trans-10b, 10c-dimethyl-10b, 10c-dihydropyrene, 21, using both NBS and PDC as oxidants. Through this route, 17 can be prepared in a 19% over-all yield by a 12 step procedure comparing to a 1.6% over-all yield and 16 steps in the previous synthesis route.
The Diels-Alder reactions of 17 with dienes (isobenzofuran and oxylylene) have been investigated under different conditions. The results suggested that quinone 17 is not a useful D-A dienophile. Thus the attempt to develop a general and efficient route to [e]-annelated derivatives of 21 via the D-A reaction of 17 was unsuccessful.
The condensation reaction of quinone 17 with malononitrile led to α,α,α',α'-tetracyano-trans-10b, 10c-dimethyl-10b, 10c-dihydropyrene-2, 7-quinodimethane, 34. As a TCNQ analogue, 34 has the potential as a organic conductor. The formation of a charge transfer complex with N, N-diethylamine was indicated by the appearance of long wave length absorption in its electronic spectrum.
The re-investigation of the addition reaction of dimethylsulfonium methylide and 17 led to the finding of a new product, 2, 7-bis(hydroxymethyl)-trans-10b, 10c-dimethyl-10b, 10c-dihydropyrene, 60. The first macrocyclophane with a DMDHP unit, 66, was synthesised by the coupling reaction of 60 and adipoyl chloride. The NMR study of 66 indicated that the two DMDHP rings are not in the face to face conformation.
The bromination of quinone 17 gave two regio isomers of dibromoquinone, 1,8-dibromo-trans-lOb, 10c-dimethyl-10b, 10c-dihydropyrene-2, 7-quinone, 82, and 1,6-dibromo-trans-lOb, 10c-dimethyl-10b, 10c-dihydropyrene-2, 7-quinone, 83. From these two isomers, 1,8-dibromo-trans-lOb, 10c-dimethyl-10b, 10c-dihydropyrene, 94, and 1,6-dibromo-trans-10b, 10c-dimethyl-10b, 10c-dihydropyrene, 96, were synthesised.