TY - JOUR
T1 - Further BF3·Et2O-catalyzed cycloadditions of sesquiterpenic p-benzoquinones
AU - Joseph-Nathan, Pedro
AU - Burgueño-Tapia, Eleuterio
AU - Santillan, Rosa L.
PY - 1993/10
Y1 - 1993/10
N2 - Cycloaddition reactions of O-methylperezone [4], O-methyl-6-methoxyperezone [13], the mixture of O-angeloyl-6-methoxyperezone [14] and O-methyl-6-angeloxyperezone [15], 6-methoxyperezone [16], and O-methyl-6-hydroxyperezone [17] are described. The results obtained from 16 and 17 allow confirmation of previous suggestions indicating that BF3 Et2O-catalyzed reactions of these quinones afford pipitzols or pipitzol derivatives when position 6 is either free or has a protected alcohol, while they afford perezinone: BF2 [10] and/or perezinone [21] when a free hydroxyl group is present at C-6. The structures of 7-methoxy-α-pipitzol [18] and 7-methoxy-β-pipitzol [19], obtained from 13, were independently confirmed by single crystal X-ray diffraction analyses.
AB - Cycloaddition reactions of O-methylperezone [4], O-methyl-6-methoxyperezone [13], the mixture of O-angeloyl-6-methoxyperezone [14] and O-methyl-6-angeloxyperezone [15], 6-methoxyperezone [16], and O-methyl-6-hydroxyperezone [17] are described. The results obtained from 16 and 17 allow confirmation of previous suggestions indicating that BF3 Et2O-catalyzed reactions of these quinones afford pipitzols or pipitzol derivatives when position 6 is either free or has a protected alcohol, while they afford perezinone: BF2 [10] and/or perezinone [21] when a free hydroxyl group is present at C-6. The structures of 7-methoxy-α-pipitzol [18] and 7-methoxy-β-pipitzol [19], obtained from 13, were independently confirmed by single crystal X-ray diffraction analyses.
UR - http://www.scopus.com/inward/record.url?scp=0027424634&partnerID=8YFLogxK
U2 - 10.1021/np50100a015
DO - 10.1021/np50100a015
M3 - Artículo
AN - SCOPUS:0027424634
SN - 0163-3864
VL - 56
SP - 1758
EP - 1765
JO - Journal of Natural Products
JF - Journal of Natural Products
IS - 10
ER -