
TY  - JOUR
A1  - Becker, H 
A1  - Hall, SR 
A1  - Skelton, BW 
A1  - White, AH 
T1  - Diels-Alder dimerization of a hexenylidene-substituted Benzofuran-2(3H)-one
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1983
VL  - 36
IS  - 2
SP  - 389
EP  - 395
KW  - 
UR  - https://doi.org/10.1071/CH9830389 
N2  - (Z)-7-t-Butyl-5 methoxy-3-[(Z)-2?-methoxy-5,5'-dimethyl-4'-oxohex-2'-enylidene]benzofuran-2(3H)-one has been found to undergo Diels-Alder dimerization in which the exocyclic double bond adds to the s-cis diene moiety. The stereochemistry of the Diels-Alder dimer was established by a single-crystal X-ray structure determination. Crystals of the dimer, C44H56O10, are monoclinic, P21/n, a 12.23(1), b 19.43(2), c 18.71(2) Å, &#946; 107.76(7)º, Z 4; a residual of 0.046 was obtained for the 2519 'observed' reflections. In the dimer, two benzofuranone moieties are situated so as to be vicinal spiro substituents of the cyclohexene formed in the Diels-Alder addition. The bond between the two benzofuranone units is unusually long [1.597(6)Å]. The shielding of one aromatic hydrogen in the n.m.r. spectrum of the dimer results from the disposition of the two aromatic systems. 
ER  -

