83889-76-3Relevant academic research and scientific papers
An improved asymmetric total synthesis of (+)-biotin via the enantioselective desymmetrization of a meso-cyclic anhydride mediated by cinchona alkaloid-based sulfonamide
Xiong, Fei,Chen, Xu-Xiang,Chen, Fen-Er
experimental part, p. 665 - 669 (2010/07/17)
The highly enantioselective total synthesis of (+)-biotin 1 via the Hoffmann-Roche lactone-thiolactone strategy has been achieved starting from cis-1,3-dibenzyl-2-imidazolidone-4,5-dicarboxylic acid 2 with an overall yield of 35%. Two contiguous stereogenic centers at C-3a and C-6a were established through a rapid cinchona alkaloid-based sulfonamide-mediated enantioselective alcoholysis of meso-cyclic anhydride 3 to afford (4S,5R)-cinnamyl hemiester 4h, the direct precursor to (3aS,6aR)-lactone 5 with high enantioselectivity. A one-pot installation of the 4-carboxybutyl side chain was accomplished by a Fukuyama coupling reaction of (3aS,6aR)-thiolactone 6 with the organozinc reagent prepared from ethyl 5-bromopentanoate.
Total synthesis of (+)-biotin via a quinine-mediated asymmetric alcoholysis of meso-cyclic anhydride strategy
Huang, Jian,Xiong, Fei,Chen, Fen-Er
, p. 1435 - 1442 (2008/12/20)
A concise asymmetric total synthesis of (+)-biotin 1 has been accomplished in which the absolute stereochemistry of C3a, C6a of 1 was established by utilizing an efficient and practical quinine-mediated asymmetric alcoholysis of meso-cyclic anhydride 2 in a single step, the C4 stereochemistry was installed by a direct stereoselective ionic hydrogenation of the thiolactol 7.
Intermediates to optically active cis-1,3-dibenzyl-hexahydro-1H-furo[3,4-d]imidazole-2,4-dione
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, (2008/06/13)
A process for preparing an optically active cis-1,3-dibenzylhexahydro-1H-furo[3,4-d]imidazole-2,4-dione of the formula: STR1 wherein an asterisk (*) indicates an asymmetric carbon, Bzl represents a benzyl group and the 3a- and 6a-positions take the cis-configuration, which comprises reducing selectively an optically active cis-imidazolidinedicarboxylic acid monoester of the formula: STR2 wherein R is a C1 -C6 alkyl group and Bzl is as defined above with a reducing agent at either one of the carboxyl group and the alkoxycarbonyl group in the said monoester, followed by cyclization, the said monoester being the one obtainable by hydrolysis of a cis-imidazolidinedicarboxylic acid diester of the formula: STR3 wherein R and Bzl are each as defined above with an enzymatic material having a capability of hydrolyzing the ester group in the said diester.
Asymmetric Hydrolysis of Prochiral Diesters with Pig Liver Esterase. Preparation of Optically Active Intermediates for the Synthesis of (+)-Biotin and (+)-α-Methyl-3,4-dihydroxyphenylalanine
Iriuchijima, Shinobu,Hasegawa, Keiko,Tsuchihashi, Gen-ichi
, p. 1907 - 1910 (2007/10/02)
With pig liver esterase, 1,3-dibenzyl-4,5-cis-bis(alkyloxycarbonyl)-2-oxoimidazolidine (1) was asymmetrically hydrolyzed to (4S,5R)-1,3-dibenzyl-5-alkyloxycarbonyl-2-oxoimidazolidine-4-carboxylic acid (2).This acid 2 was reduced with lithium borohydride to (4S,5R)-1,3-dibenzyl-5-hydroxymethyl-2-oxoimidazolidine-4-carboxylic acid lactone (3), which is known to be converted to (+)-biotin (4).With the same esterase, diethyl 3,4-dimethoxyphenylmethyl(methyl)malonate (5) was asymmetrically hydrolyzed to (R)-ethyl hydrogen 3,4-dimethoxyphenylmethyl(methyl)malonate (6), which can be converted to (S)-α-methyl-3,4-dihydroxyphenylalanine (L-α-methyldopa) (9).
