Photocycloaddition of Conjugated Cyclohex-2-enones to 2,3-Dimethylbuta-1,3-diene
作者:Inga Inhülsen、Kerstin Schmidt、Paul Margaretha
DOI:10.1002/hlca.201000042
日期:——
3 and 4, whereas, under these conditions, 3‐(alk‐1‐ynyl)cyclohex‐2‐enones 5 give only one cyclobutane adduct 6 regio‐ and diastereoselectively. In contrast, 3‐(alk‐1‐ynyl)‐2‐methylcyclohex‐2‐enones 10 undergo [2+2]‐cycloaddition to the same diene exclusively at the C≡C bond to afford hitherto unknown 3‐cyclobutenylcyclohex‐2‐enones 11.
A rapid access to hydroxylated benz[a]anthraquinones: Hypervalent iodine oxidation of β-naphthols
作者:Dipakranjan Mal、Harendra N. Roy、Nirmal K. Hazra、Susanta Adhikari
DOI:10.1016/s0040-4020(96)01119-2
日期:1997.2
Anionic annulation of phthalide sulfones 3 with quinone monoketals 6, accessible by phenyliodonium diacetate oxidation of naphthols 5, offers a high yielding regiospecific entry to benz[a]anthraquinones 8. Similar annulation of cyanophthalide 13 with 12, followed by photooxygenation of 14 results in a complementary route to the basic skeleton 15 of nonaromatic A-ring angucyclines. (C) 1997, Published by Elsevier Science Ltd.
DOLSON M. G.; JACKSON D. K.; SWENTON J. S., J. CHEM. SOC. CHEM. COMMUN., 1979, NO 7, 327-329