115148-10-2Relevant academic research and scientific papers
Addition of silyloxydienes to 2-substituted 1,4-benzoquinones and 1,4-naphthoquinones
Brimble, Margaret A.,Elliott, Richard J.R.
, p. 7715 - 7730 (1997)
Addition of 1-trimethylsilyloxybuta-1,3-diene 2 to the quinones 4,5,6,17,18,19,20 bearing formyl, acetyl, methoxycarbonyl or carboxamide substituents at C-2, afforded the Diels-Alder adducts 11,12,13,25,26,27,28 whereas addition of 2-trimethylsilyloxyfuran 3 afforded the fragmentation products 29,30,31,35,36,37,38. Quinones 7,21 bearing a carboxyl group at C-2 afforded 1,4-naphthoquinone and 9,10-anthracenedione with 2 and no adducts were isolated from reaction with 3. Benzoquinone-sulfide 8 afforded Diels-Alder adduct 14 and fragmentation product 32 with 2 and 3 respectively whereby reaction occurred on the less substituted double bend. No adducts were isolated upon treatment of naphthoquinone-sulfide 22 with either 2 or 3. The Diels-Alder adducts of benzoquinone-sulfoxide 9 and naphthoquinone-sulfoxide 23 with 2 underwent facile aromatisation to 1,4-naphthoquinone and 9,10-anthracenedione with 2. Addition of 3 to 9 afforded fragmentation product 33 whereas analogous reaction with 23 was unsuccessful. Addition of dienes 2,3 to benzoquinone-sulfone 10 afforded fragmentation products 16,34 respectively, whereas naphthoquinone-sulfone 24 afforded 9,10-anthracenedione with 2 and no products with 3.
Synthesis of the cis-3a,8b-Dihydrofurobenzofuran-2(3H)-one Ring System via a Furofuran Annulation to Activated Benzoquinones
Brimble, Margaret A.,Brimble, Mark T.,Gibson, Jennifer J.
, p. 179 - 184 (2007/10/02)
The uncatalysed addition of 2-(trimethylsiloxy)furan (4) to the 1,4-benzoquinones (5a-e) containing electron-withdrawing groups at C-2 gave the cis-3a,8b-dihydrofurobenzofuran-2(3H)-ones (6a-e) in 51-76percent yields.The 1,4-benzoquinones (5f, g, h) without electron-withdrawing groups at C-2 failed to undergo the furofuran annulation, with none of the desired adducts (6f, g, h) being isolated.The carboxylic acid adduct (6i; R=CO2H) was prepared indirectly by reductive hydrolysis of either the phenacyl adduct (6e) or the trichloroethyl ester adduct (6d) using zinc in acetic acid (9).Treatment of the methyl ketone adduct (6b) with acid effected a ring opening to the corresponding (benzofuran-2-yl)acetic acid.
1,4-ADDITION OF 2-TRIMETHYLSILYLOXYFURAN TO QUINONES: A FACILE ROUTE TO THE FUROBENZOFURAN NUCLEUS
Brimble, Margaret A.,Gibson, Jennifer J.,Baker, Raymond,Brimble, Mark T.,Kee, Alex A.,O'Mahony, Mary J.
, p. 4891 - 4892 (2007/10/02)
The uncatalysed addition of 2-trimethylsilyloxyfuran (3) to a range of activated quinones (4) and (6) yields the crystalline adducts (5) and (7) in 51-91percent yield.This novel furofuran-annulation to a quinone system provides a facile entry to the furobenzofuran ring system.
