Transformation of D-erythrose to some pseudoaldopentofuranoses. Syntheses of (1S,2R,3S,4S)-, (1R,2R,3S,4S)-, and (1R,2S,3S,4S)-2,3,4-trihydroxy-1-(hydroxymethyl)cyclopentanes and (1R,2S,3R,4R)-2,3-dihydroxy-4-(hydroxymethyl)-1-cyclopentanamine
Variable Strategy toward Carbasugars and Relatives. 2.1 Diversity-Based Synthesis of β-d-Xylo, β-d-Ribo, β-l-Arabino, and β-l-Lyxo 4a-Carbafuranoses and (4a-Carbafuranosyl)thiols
摘要:
The silyloxy diene-based construction of carbasugars, previously exploited for the synthesis of four carbocyclic furanose and pyranose analogues, has been investigated further. By introducing a novel silylative cycloaldolization protocol and by adjusting a couple of minor transformations, the efficiency of this synthetic sequence was greatly improved. Through a series of lactone/thiolactone aldehyde cyclization precursors, four carbafuranoses (4a-carba-beta -D-xylofuranose, 4a-carba-beta -D-ribofuranose, 4a-carba-beta -L-arabinofuranose, and 4a-carba-beta -L-lyxofuranose) and four (carbafuranosyl)thiols [(4a-carba-beta -D-xylofuranosyl)thiol, (4a-carba-beta -D-ribofuranosyl)thiol, (4a-carba-beta -L-arabinofuranosyl)thiol, and (4a-carba-beta -L-lyxofuranosyl)thiol] were assembled. From this study, it was shown that these constructions tolerate a variety of precursors, and in many instances, they are suitable for scaling-up.
Synthesis of 4a-carba-β-l-lyxofuranose, 4a-carba-β-l-arabinofuranose and 2,2,5-trimethyl-3a,6a-dihydro-cyclopenta[1,3]dioxol-4-one using Mn/CrCl3 mediated domino reactions and ring closing metathesis
A common method for the synthesis of 4a-carba-beta-L-lyxofuranose and 4a-carba-beta-L-arabinofuranose from D-mannose and 2,2,5-trimethy1-3a,6a-dihydro-cyclopenta[1,3]dioxol-4-one from o-ribose is described using catalytic Nozaki-Hiyama-Kishi (NHK) conditions and ring closing metathesis (RCM). In this transformation, omega-deoxy-omega-iodo manno/ribo furanoside undergoes reductive elimination in the presence of Mn/CrCl3 to give the corresponding olefin-aldehyde which was trapped by nucleophile under the same conditions to afford the desired diolefinic species. The ring closing metathesis reaction on these diolefinic species with Grubbs second generation catalyst produced the required carbocycles. (c) 2012 Elsevier Ltd. All rights reserved.
TADANO, KIN-ICHI;HOSHINO, MASAHIDE;OGAWA, SEIICHIRO;SUAMI, TETSUO, J. ORG. CHEM., 53,(1988) N 7, 1427-1432