The stereocontrolled synthesis of phthalic acid 4,5-cis-dihydrodiol. An unambiguous structural assignment of the bacterial metabolite of phthalic acid
摘要:
The stereocontrolled synthesis of the extremely labile phthalic acid 4,5-cis-dihydrodiol (1) has been achieved in a highly efficient manner in seven steps from bis[2-(trimethylsilyl)ethyl] fumarate (2). The Diels-Alder adduct 3 of the fumarate with furan has been converted into first exo-cis-diol 4 and then its acetonide 5. Treatment of acetonide 5 with lithium hexamethyldisilazide results in the regioselective formation of olefinic alcohol 6. Following the introduction of the second double bond into the cyclohexene ring system, the highly sensitive deprotection of the acetonide group of dihydrodiol diester acetonide 7 can be effected under iodine catalysis. The hydrolysis of the 2-(trimethylsilyl)ethyl ester group has been achieved by treatment with tetra(n-butyl)-ammonium fluoride in THF. This synthesis constitutes an unambiguous assignment of the structure and stereochemistry of the microbial metabolite of phthalic acid.
The stereocontrolled synthesis of phthalic acid 4,5-cis-dihydrodiol. An unambiguous structural assignment of the bacterial metabolite of phthalic acid
摘要:
The stereocontrolled synthesis of the extremely labile phthalic acid 4,5-cis-dihydrodiol (1) has been achieved in a highly efficient manner in seven steps from bis[2-(trimethylsilyl)ethyl] fumarate (2). The Diels-Alder adduct 3 of the fumarate with furan has been converted into first exo-cis-diol 4 and then its acetonide 5. Treatment of acetonide 5 with lithium hexamethyldisilazide results in the regioselective formation of olefinic alcohol 6. Following the introduction of the second double bond into the cyclohexene ring system, the highly sensitive deprotection of the acetonide group of dihydrodiol diester acetonide 7 can be effected under iodine catalysis. The hydrolysis of the 2-(trimethylsilyl)ethyl ester group has been achieved by treatment with tetra(n-butyl)-ammonium fluoride in THF. This synthesis constitutes an unambiguous assignment of the structure and stereochemistry of the microbial metabolite of phthalic acid.