Premium
Ninhydrin as a Source of Naphthoquinone Acetals and Benzocycloheptenetrione Derivatives, and the Trapping of an Oxacarbene Derived from a Cyclopentanone
Author(s) -
Leinweber Dirk,
Schnebel Matthias,
Wartchow Rudolf,
Wey Hans G.,
Butenschön Holger
Publication year - 2002
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/1099-0690(200207)2002:14<2385::aid-ejoc2385>3.0.co;2-s
Subject(s) - chemistry , cyclopentanone , ring (chemistry) , naphthoquinone , maleic anhydride , acrylonitrile , yield (engineering) , derivative (finance) , cyclopentene , ninhydrin , photochemistry , medicinal chemistry , stereochemistry , organic chemistry , catalysis , biochemistry , materials science , amino acid , economics , financial economics , copolymer , metallurgy , polymer
1,3‐Bis(ethylenedioxy)‐2‐indanone ( 2 ) was shown to react with some dienophiles to give naphthoquinone acetals under photochemical reaction conditions, presumably by photodecarbonylation via the corresponding ortho ‐quinodimethane. With maleic anhydride the highly oxygenated benzocycloheptane derivative rac ‐ 12 was obtained in good yield. In a similar manner, upon irradiation in the presence of acrylonitrile a 2:1 mixture of ring‐expanded regioisomers rac ‐ 13 and rac ‐ 14 was obtained. Irradiation in the presence of fumarodinitrile unexpectedly gave the spirocyclic compound rac ‐ 15 , which was characterized by X‐ray crystallography. rac ‐ 15 is the trapping product of oxacarbene 16 , thus demonstrating a rare case of a ring expansion of a cyclopentanone to give a six‐membered ring oxacarbene, here leading to an orthoester. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)