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Pseudosugars, 37. Preparation of Versatile Intermediates for Ether‐Linked 5a‐Carba Oligosaccharides: Synthesis of 5a‐Carba‐β‐ D ‐Glc p NAc‐(1→4)‐ D ‐Man p
Author(s) -
Ogawa Seiichiro,
Hirai Keisuke,
Ohno Masatsugu,
Furuya Takashi,
Sasaki ShinIchi,
Tsunoda Hidetoshi
Publication year - 1996
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.199619960505
Subject(s) - disaccharide , chemistry , ether , ketone , stereochemistry , derivative (finance) , protecting group , organic chemistry , alkyl , financial economics , economics
Coupling of 1,2‐anhydro‐3‐ O ‐benzyl‐4,6‐ O ‐benzylidene‐5a‐carba‐β‐ D ‐mannopyranose ( 3 ) with 1,6‐anhydro‐2,3‐ O ‐isopropylidene‐β‐ D ‐mannopyranose ( 4 ) afforded a 5a′‐carba disaccharide derivative linked by an ether bridge with α‐ manno configuration. This compound 5 was transformed into three stereoisomers in regard to the configurations at C‐1′ and C‐2′. Thus, the free 2′‐hydroxyl group was oxidized, and the resulting ketone 8 was isomerized at C‐1′ to 11 by treatment with potassium tert ‐butoxide. Reduction of the ketones 8 and 11 with l ‐selectride afforded selectively the synthetic useful intermediate ether‐linked 5a′‐carba disaccharides 9 , 12 , and 14 with α‐ gluco , β‐ gluco , and β‐ manno configurations, respectively. 5a‐Carba sugar analog 2 of biologically interesting disaccharide β‐ D ‐Glc p NAc‐(1→4)‐ D ‐Man p ( 1 ) was synthesized.