A NOVEL PENTOSE SYNTHESIS VIA PALLADIUM(II)-CATALYZED CYCLIZATION OF AN UNSTABLE HEMIACETAL

作者：Awasaguchi Ken ichiro^*; Miyazawa Masahiro; Uoya Ikuyo; Inoue Koichi; Nakamura Koji; Yokoyama Hajime; Hirai Yoshiro

来源：Heterocycles, 2010, 81(9): 2105-2121.

DOI：10.3987/COM-10-12001

• Palladium Catalyst
• Hemiacetal
• Tetrahydrofuran
• Cyclization
• Pentose

PdCl(2)(PhCN)(2) (5 mol%)-catalyzed cyclization of a hemiacetal derived from (E,2S,3R)-2,3-isopropylidenedioxy-6-(tetrahydro-2H-pyran-2-yl)-4-hexenal and methanol gave substituted furanoside in moderate yield, exclusively via 5-exo-mode cyclization, without the need for a reoxidant. New stereogenic centers at C1 and C4 on the tetrahydrofuran ring showed preferential 1R and 4R stereochemistry due to anomeric effect (n(omicron)-sigma(c-omicron)*) and A(1,2) strain, respectively. This methodology was applied to stereocontrolled synthesis of pentoses: D-ribose and L-lyxose.

• 出版日期2010-9-1