TY  - JOUR
AB  - Two independent syntheses of the new centrotetraindan 2, a trifuso, Cs-symmetrical isomer of fenestrindan 1, are described. The first approach is based on the endo-phenyldiindanone 7, which is converted into 2 by benzylation to ketone 8 and subsequent cyclodehydration with polyphoshoric acid. The second, more efficient approach is based on the diindan-dione 17, which is converted into ketol 19 in two steps, which, in turn, is subjected to a three-step cyclodehydration-reduction-cyclodehydration sequence via 26 and 27 to give 2 in 8% overall yield. Some limits of the cyclodehydration of diindan alcohols and ketones are demonstrated with regard to effects of steric crowding and fragmentation of the carbon skeleton. The steric hindrance of endo-phenyl-substituted diindans is demonstrated in the case of ketone 26.
DA  - 1992
DO  - 10.1002/cber.19921250624
KW  - Cyclodehydration
KW  - Centropolyindans
KW  - Polycyclic compounds
KW  - Propellanes
KW  - Triquinacenes
LA  - eng
IS  - 6
M2  - 1461
PY  - 1992
SN  - 0009-2940
SP  - 1461-1469
T2  - Chemische Berichte
TI  - Benzoanellated centropolyquinanes, 12. Trifuso-centrotetraindan - two syntheses of a new centropolyindan
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-17742429
Y2  - 2024-11-22T05:33:58
ER  -