87637-50-1Relevant 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.
