TY  - JOUR
AB  - The syntheses of tribenzotriquinacene (1a) and five centro-substituted derivatives, 1b-1e and 1g, as well as of the related diindan 13 are reported. The three-step synthetic sequences include the reduction of suitably substituted 2-benz-hydryl-1,3-indandiones 3 to the corresponding 1,3-indandiols 4 and the twofold cyclodehydration of the latter to close two additional five-membered rings at a time. Although the yields of the cyclodehydration step 4 · 1 are only low to moderate (10-33%), the overall approach allows the preparation of 5-50-gram amounts of the centropolyindans in most cases by starting from simple 1,3-indandiones 2a-2c. This includes the new synthesis of the parent tribenzotriquinacene (1a). The related Cs-symmetrical diindan, 4b,9,9a,10-tetrahydroindeno[1,2-a]indene (13), has been prepared in high yield by using the same cyclodehydration technique. Scope and limitations of the double cyclodehydration strategy are described concerning the synthesis of 1,3-indandiones with bulky substituents at C-2 and the cyclization of 1,3-indandiols with an aptitude to undergo heterolytic cleavage of an exocyclic C-2-C- bond, in particular 4f. The course of the reduction of the 2,2-disubstituted 1,3-indandiones with lithium aluminum hydride is discussed on the basis of the stereochemistry of the product 1,3-indandiols.
DA  - 1992
DO  - 10.1002/cber.19921250623
KW  - 3-indandiones
KW  - Cyclodehydration
KW  - Triquinacenes
KW  - Polycyclic compounds
KW  - 1
KW  - Centropolyindans
KW  - 3-Indandiols
LA  - eng
IS  - 6
M2  - 1449
PY  - 1992
SN  - 0009-2940
SP  - 1449-1460
T2  - Chemische Berichte
TI  - Benzoanellated centropolyquinanes, 11. Synthesis of tribenzotriquinacene and some centro-substituted derivatives
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-17742456
Y2  - 2024-11-22T04:12:54
ER  -