Reaction of tris(pentafluorophenyl)phosphine with various nucleophiles (DMF, HMPA, HEPA, diethylformamide, hydrazine, UDMH, phenylhydrazine, formamide, and aniline) gave exclusively the replacement of all three para fluorines with the exception of aniline, phenylhydrazine, and formamide which gave mixtures of the mono- and bis-4-substituted phosphines. Sodium bisulphide and various alkoxides led mainly to C—P bond rupture though some alkoxides did under certain conditions give some of the expected substitution product. 19F, 31P, and 1H nmr and mass spectral data are presented.

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The methyl 4,6-O-benzylidene-2,3-dideoxy-3-nitrohex-2-enopyranosides having the β-D-erythro (1), α-D-erythro (2), β-D-threo (3), and α-D-threo (4) configurations reacted with diazomethane to give high yields of 2,3-(1′-pyrazolino-3′,4′) derivatives (5–8). The pyrazolines 5 and 6 (from 1 and 2) were deduced on the basis of nuclear magnetic resonance and optical rotatory dispersion data to possess the β- and α-D-gluco configurations, and 7 and 8 (from 3 and 4), to have the β- and α-D-ido configurations, respectively. Thermolysis of 5, 6, and 8 led to the methyl-branched, nitroolefinic glycosides 9, 10, and 11 (the 2-C-methyl derivatives of 1, 2, and 4), whereas 7 afforded the corresponding 2,3-C-methylene derivative 12, a cyclopropano sugar. The α-anomeric cyclopropano derivative 13 was obtained from 8 by decomposition on silica gel.

Treatment of methyl 3,6-dideoxy-2,4-di-O-methylsulfonyl-3-nitro-α-L-glucopyranoside (2) with sodium acetate and acetic acid in acetone gave methyl 4-O-acetyl-2,3,6-trideoxy-3-nitro-α-L-erythro-hex-2-enopyranoside (3) as a kinetic product, and the 2-O-acetyl-3,4,6-trideoxy-3-nitro-α-L-threo-hex-3-eno isomer 4 as the thermodynamically preferred product. Treatment of 2 or 4 with sodium borohydride produced a separable mixture of methyl 2,3,4,6-tetradeoxy-3-nitro-α-L-threo-hexopyranoside (5) and its α-L-erythro epimer (6), the latter being convertible into the former by base-catalyzed epimerization. Acid hydrolysis of 5 and 6 afforded the corresponding free nitro sugars 7 and 8. Catalytic hydrogenation of 5 led to the corresponding amino glycoside, isolated as the acetate 9 or hydrochloride 10; similarly, 6 gave the epimeric amine which was isolated as its acetate 14 or picrate 15. N-Trifluoroacetylation of 9 provided the N-trifluoroacetyl glycoside 12 which was hydrolyzed to give a 49% yield (overall from 2) of 2,3,4,6-tetradeoxy-3-trifluoroacetamido-L-threo-hexose (4-deoxy-N-trifluoroacetyldaunosamine, 13). Analogously, 14 afforded the epimeric N-trifluoroacetyl glycoside 17 which was hydrolyzed to give a 28% overall yield of 2,3,4,6-tetradeoxy-3-trifluoroacetamido-L-erythro-hexose (4-deoxy-N-trifluoroacetylristosamine, 18).