Steric effects in di- and tri-arylmethane dyes. Part X. Electronic absorption spectra of bridged derivatives of malachite green and crystal violet
作者:C. Aaron、C. C. Barker
DOI:10.1039/j29710000319
日期:——
The isopropylidene group has been introduced singly and doubly into ortho-positions of Malachite Green and Crystal Violet in order to determine molecular conformation. The electronicabsorptionspectra of these dyes are discussed with particular reference to their bearing on intensity variations of the first band of ortho-derivatives of Malachite Green. The introduction of two isopropylidene bridges
Rearrangements of Cyclobutenones. Electrocyclic Ring Closure and Thermal Ring Expansions of 3-Allenyl- and 3-Alkynyl-2-dienyl-4,4- dimethoxycyclobutenones
作者:Antonio R. Hergueta、Harold W. Moore
DOI:10.1021/jo010919g
日期:2002.2.1
Thermal rearrangements of 2-allenyl- and 2-alkynyl-3-(2-ethenylphenyl)-4,4-dimethoxycyclobutenones were studied. At ambient temperature, the allenyl compounds undergo an electrocyclic cascade to give bicyclo[4.2.0]octadienyl-fused cyclobutenones. These unusual tetracyclic cyclobutenones were shown to be viable synthetic precursors to benzo[a]anthracene-7,12-diones, compounds representing the framework
A convergent approach to substituted phenanthrenes via quinol ketals
作者:Tina M. Marks、Gary W. Morrow
DOI:10.1016/s0040-4039(00)74186-4
日期:1992.4
Reaction of 2'-lithiostyrenes with p-benzoquinone monoketals gives p-quinol ketals which undergo Lewis acid-catalyzed cyclization and aromatization, affording 2-methoxyphenanthrenes.