5-deoxy-5-phosphino- and-5-phosphinyl

MHz, H-N.m.r. Parameters for 5-Deoxy-5-C-phosphino- and -phosphinyl-aldopyranoses in CDC1 ... 

Reduction of 10 with lithium aluminum hydride (LAH) in ether furnished19 an intermediate, presumably the phosphine derivative 11, which was treated with acid to effect ring enlargement, giving the 5-phosphino-D-xylopyranose derivative 14. This compound was immediately converted by air oxidation19 into the stable crystalline compounds, 5-deoxy-3-0-methyl-5-C-(phosphinyl)-D-xylopyranose (15) and the 5-C-(hydroxyphosphinyl) derivative 16 in overall yields of 15 and 3.5%, respectively, from 10. Compound 16 was obtained in 90% yield from 15 by oxidation with bromine.19 No mutarotation was observed19 for compounds 15 and 16 in water during 48 h. 

When either of the two methods in the previous Subsection is employed in order to introduce a phosphino (or phosphinyl) group at C-5 of 5-deoxy-D-xyZo-hexofuranoses, only 5-deoxy-5-phosphino- (or -5-phos-phinyl)- L-idopyranoses are produced for instance, 50 — 60 (and 64) — 63 (and 65), and 73 — 78 — 85 — 88 — 90. Therefore, in order to prepare hexopyranoses of the D-gluco type having phosphorus in the hemiacetal ring, an alternative approach had to be devised. 

---