Stereocontrolled transformation of nitrohexofuranoses into cyclopentylamines via 2-oxabicyclo[2.2.1]heptanes. Part 6: synthesis and incorporation into peptides of the first reported 2,3-dihydroxycyclopentanecarboxylic acid

Herein we report the intramolecular alkylation of nitronates of methyl-5-O-benzyl-3,6-deoxy-6-nitro-β-d-glucofuranoside and methyl-5-O-benzyl-3,6-deoxy-6-nitro-α-d-glucofuranoside into the corresponding 2-oxabicyclo[2.2.1]heptane derivatives. Similarly, methyl-3-O-benzyl-5-deoxy-5-nitromethyl-β-d-xylofuranoside and methyl-3-O-benzyl-5-deoxy-5-nitromethyl-α-d-xylofuranoside were cyclized to (1R,3R,4S,5R,7R)-7-benzyloxy-3-methoxy-5-nitro-2-oxabicyclo[2.2.1]heptane and (1R,3S,4S,5R,7R)-7-benzyloxy-3-methoxy-5-nitro-2-oxabicyclo[2.2.1]heptane, respectively. These 2-oxabicyclo[2.2.1]heptane derivatives were eventually transformed into enantiopure methyl (1S,2S,3R,4S,5R)-2-amino-2,3-dihydroxycyclopentanecarboxylate and this novel β-amino acid was incorporated into peptides.

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5-O-Benzyl-3-deoxy-1,2-O-isopropylidene-6-O-tert-butyldiphenylsilyl-α-d-glucofuranoseC32H40O5Si[α]D25=-13.8 (c 1.1, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1R,2R,4S,5R)

5-O-Benzyl-3-deoxy-1,2-O-isopropylidene-α-d-glucofuranoseC16H22O5[α]D27=-0.2 (c 1.0, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1R,2R,4S,5R)

5-O-Benzyl-3-deoxy-1,2-O-isopropylidene-6-O-p-toluenesulphonyl-α-d-glucofuranoseC23H28O7S[α]D20=-12 (c 0.5, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1R,2R,4S,5R)

5-O-Benzyl-3,6-dideoxy-1,2-O-isopropylidene-6-iodo-α-d-glucofuranoseC16H21IO4[α]D20=-11 (c 1.3, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1R,2R,4S,5S)

5-O-Benzyl-3,6-dideoxy-1,2-O-isopropylidene-6-nitro-α-d-glucofuranoseC16H21NO6[α]D25=-12 (c 1.0, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1R,2R,4S,5R)

5-O-Benzyl-3,6-dideoxy-6-nitro-α-d-glucofuranoseC13H15NO6[α]D25=+39.6 (c 1.8, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (2R,4S,5R)

(1S,3S,4R,5S,6R)-6-(Benzyloxy)-3-methoxy-5-nitro-2-oxabicyclo[2.2.1]heptaneC14H17NO5[α]D27=+58 (c 0.5, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1S,3R,4S,5S,6R)

(1S,3S,4R,5S,6R)-6-(Benzyloxy)-3-methoxy-5-nitro-2-oxabicyclo[2.2.1]heptaneC14H17NO5[α]D25=+32 (c 1.0, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1S,3S,4R,5S,6R)

3-O-Benzyl-5-deoxy-5-nitromethyl-d-xylono-1,4-lactoneC13H15NO6[α]D25=+32.0 (c 1.8, MeOH)Source of asymmetry: d-glucoseAbsolute configuration: (2R,3R,5R)

Methyl-3-O-benzyl-5-deoxy-5-nitromethyl-α-d-xylofuranosideC16H22O5[α]D27=-15 (c 1.0, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1S,2R,3R,4R)

Methyl-3-O-benzyl-5-deoxy-5-nitromethyl-β-d-xylofuranosideC16H22O5[α]D27=-59 (c 1.0, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1R,2R,3R,4R)

(1R,3R,4S,5R,7R)-7-Benzyloxy-3-methoxy-5-nitro-2-oxabicyclo[2.2.1]heptaneC14H17NO5[α]D27=-40.5 (c 2.0, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1R,3R,4S,5R,7R)

(1R,3R,4S,5R,7R)-7-Benzyloxy-3-methoxy-5-nitro-2-oxabicyclo[2.2.1]heptaneC14H17NO5[α]D25=-14.8 (c 1.5, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1R,3R,4S,5R,7R)

(1S,2R,3R,5R)-Methyl 2-(benzyloxy)-3-hydroxy-5-nitrocyclopentanecarboxylateC14H17NO6[α]D20=+113.0 (c 1.15, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1S,2R,3R,5R)

(1S,2R,3R,5R)-Methyl 2-(benzyloxy)-5-(tert-butoxycarbonylamino)-3-hydroxy-cyclopentanecarboxylateC19H27NO6[α]D20=-3.7 (c 1.1, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1S,2R,3R,5R)

(1S,2R,3R,5R)-Methyl 2-(benzyloxy)-5-(tert-butoxycarbonylamino)-3-hydroxy-1-(methoxycarbonylglycylcarbamoyl)cyclopentaneC21H30N2O7[α]D20=+21.6 (c 1.4, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1S,2R,3R,5R)

1S,2R,3R,5R)-Methyl 2-(benzyloxy)-5-(benzyloxycarbonylglycylamino)-3-hydroxy-1-(methoxycarbonylglycylcarbamoyl)cyclopentaneC26H31N3O8[α]D20=+6.0 (c 1.0, CHCl3)Source of asymmetry: d-glucoseAbsolute configuration: (1S,2R,3R,5R)