title: Stereoselective Synthesis of Spiro Bis-C,C-α-arylglycosides by Tandem Heck Type C-Glycosylation and Friedel-Crafts Cyclization.
abstract: Spiro bis-C,C-α-arylglycosides were synthesized in three steps in 78-85% overall yields starting from exo-glycals. The initial Heck type C-aryl addition of exo-glycals with arylboronic acids afforded α-aryl-β-substituted C-glycosides with exclusive α-stereoselectivity. Among the products, β-ethanal α-aryl C-glycosides further reacted with alkylthiol in the presence of InCl3, followed by in situ Friedel-Crafts cyclization to yield the desirable final products. We proposed a mechanism to explain how the α-aryl group serves as a main determinant of the cyclization.
authors.affiliation: School of Pharmacy, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.|Graduate Institute of Pharmaceutical Chemistry, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.
authors.forename: Yen-Bo
authors.initials: YB
authors.lastname: Chen
authors.affiliation: Graduate Institute of Pharmaceutical Chemistry, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.
authors.forename: Shi-Hao
authors.initials: SH
authors.lastname: Liu
authors.affiliation: School of Pharmacy, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.|Chinese Medicinal Research and Development Center, China Medical University Hospital , No. 2, Yude Road, Taichung, 40447, Taiwan.
authors.forename: Min-Tsang
authors.initials: MT
authors.lastname: Hsieh
authors.affiliation: School of Pharmacy, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.|Graduate Institute of Pharmaceutical Chemistry, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.
authors.forename: Chih-Shiang
authors.initials: CS
authors.lastname: Chang
authors.affiliation: Institute of Biological Chemistry, Academia Sinica , No. 128, Academia Road, Section 2, Nan-Kang, Taipei, 11529, Taiwan.
authors.forename: Chun-Hung
authors.initials: CH
authors.lastname: Lin
authors.affiliation: School of Pharmacy, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.|Graduate Institute of Pharmaceutical Chemistry, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.
authors.forename: Chen-Yin
authors.initials: CY
authors.lastname: Chen
authors.affiliation: School of Pharmacy, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.|Graduate Institute of Pharmaceutical Chemistry, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.
authors.forename: Po-Yen
authors.initials: PY
authors.lastname: Chen
authors.affiliation: School of Pharmacy, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.|Graduate Institute of Pharmaceutical Chemistry, China Medical University , No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.
authors.forename: Hui-Chang
authors.initials: HC
authors.lastname: Lin