A concise and practical stereoselective synthesis of ipragliflozin L-proline

• Shuai Ma,
• Zhenren Liu,
• Jing Pan,
• Shunli Zhang and
• Weicheng Zhou

Beilstein J. Org. Chem. 2017, 13, 1064–1070, doi:10.3762/bjoc.13.105

• 10.3762/bjoc.13.105 Abstract A concise and practical stereoselective synthesis of ipragliflozin L-proline was presented starting from 2-[(5-iodo-2-fluorophenyl)methyl]-1-benzothiophene and 2,3,4,6-tetra-O-pivaloyl-α-D-glucopyranosyl bromide without catalyst via iodine–lithium–zinc exchange. The overall

• yield was 52% in three steps and the product purity was excellent. Two key diastereomers were prepared with efficient and direct access to the α-C-arylglucoside. Keywords: arylzinc derivative; β-C-arylglucoside; diastereomer impurity; ipragliflozin L-proline; stereoselective synthesis; Introduction

• , (ipragliflozin L-proline 1, (1S)-1,5-anhydro-1-C-{3-[(1-benzothiophen-2-yl)methyl]-4-fluorophenyl}-D-glucitol (2S)-pyrrolidine-2-carboxylic acid (1:1), Figure 1), was launched into the Japanese market in January 2014 [7][8]. Due to its efficacy and safety, 1 can be used as monotherapy or in combination with