TY - JOUR
T1 - A chemo-enzymatic elaboration of a quarternary chiral center
T2 - An alternative approach to the side chain of furaquinocin D
AU - Akeboshi, Tomohiro
AU - Ohtsuka, Yoshikazu
AU - Sugai, Takeshi
AU - Ohta, Hiromichi
N1 - Funding Information:
Acknowledgments: The authors thank to Profs. Keisuke Suzuki and Takashi Matsumoto, and Dr. Takeshi Saito, Tokyo Institute of Technology, and Prof. Noritaka Chida of Dept of Applied Chemistry, Keio University for their discussion and help throughout this study. We are indebted to Amano Pharmaceutical Co. and Novo Nordisk Co. for the supply of lipases. T.S and T.A. express sincere thanks to the editor and referees, who allowed us tore-examine the preferential degradation experiment. This work was supported by a Grant-in-Aid for Scientific Research (No. 09231244) from the Ministry of Education, Science, Sports and Culture, Japan, and Keio Foundation.
PY - 1998/6/25
Y1 - 1998/6/25
N2 - A new approach to ethyl (2R,3R)-2-t-butyldimethytsilyloxymethyl-3- hydroxy-2-methylbutanoate, a compound which is related to a synthetic intermediate of the side chain of furaquinocin D, is described. The characteristic feature of this compound is a quarternary chiral center and an adjacent secondary alcohol, both of which are in a stereochemically defined state, and the setup of these functionalities was achieved by a combination of stereoselective chemical and enzymatic reactions. The reduction of ethyl 2-hydroxymethyl-2-methyl-3-oxobutanoate with excess NaBH4 afforded (2R*,3R*)-(±)-hydroxy ester with a high diastereomeric excess. After protecting the primary hydroxy group as TBDMS ether, the optical resolution was achieved by lipase-catalyzed hydrolysis of the corresponding chloroacetate in a highly enantioselective manner.
AB - A new approach to ethyl (2R,3R)-2-t-butyldimethytsilyloxymethyl-3- hydroxy-2-methylbutanoate, a compound which is related to a synthetic intermediate of the side chain of furaquinocin D, is described. The characteristic feature of this compound is a quarternary chiral center and an adjacent secondary alcohol, both of which are in a stereochemically defined state, and the setup of these functionalities was achieved by a combination of stereoselective chemical and enzymatic reactions. The reduction of ethyl 2-hydroxymethyl-2-methyl-3-oxobutanoate with excess NaBH4 afforded (2R*,3R*)-(±)-hydroxy ester with a high diastereomeric excess. After protecting the primary hydroxy group as TBDMS ether, the optical resolution was achieved by lipase-catalyzed hydrolysis of the corresponding chloroacetate in a highly enantioselective manner.
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U2 - 10.1016/S0040-4020(98)00400-1
DO - 10.1016/S0040-4020(98)00400-1
M3 - Article
AN - SCOPUS:0032565996
SN - 0040-4020
VL - 54
SP - 7387
EP - 7394
JO - Tetrahedron
JF - Tetrahedron
IS - 26
ER -