C-Hydroxymethylation

Pyrrole has been condensed under alkaline conditions with formaldehyde to give products of either N- or C-hydroxymethylation (Scheme 22). Although acid-catalyzed hydroxy-methylation is not a practical possibility, by addition of a reducing agent to the reaction mixture overall reductive alkylation can be achieved (Scheme 23). 

Chemical Name 0-2-Deoxy-2-(methylamino)-a-L-glucopyranosyl-(1 2)-0-5-deoxy-3-C-(hydroxymethyl)-a-L-lyxofuranosyl-(1 4)-N,N -bis(aminoiminomethyl)-D-streptamine... 

CN 3,4-dideoxy-4-[[2-hydroxy-l-(hydroxymethyl)ethyl]amino]-2-C-(hydroxymethyl)-D-epi-inositol... 

Before 1983, branched-chain sugars had not been found in bacterial polysaccharides, but there are now five examples belonging to this class. The LPS from Coxiella burned phase I contains both 6-deoxy-3-C-methyl-L-gulose (L-virenose) as pyranoside (12) and 3-C-(hydroxymethyl)-L-lyxose as furan-oside (13). Another 6-deoxy-3-C-methylhexose, having the manno configuration, is a component of the Nitrobacter hamburgiensis 0-antigen. ... 

C7H14Oe Methyl 2-C-(hydroxymethyl)-/ -D-ribopyranoside [methyl / -D-hamameloside] (MHAMEL)850... 

CeHu06- Ca2+ Calcium 3-deoxy-2-C-(hydroxymethyl)-D-erythro-pentonate CAGLIS10 31 364... 

Vasella has used deoxy-nitro sugars for the synthesis of various biologically important carbohydrates,10 and the radical nitromethylation of deoxy-nitro sugars has been used for synthesis of fructose 6-phosphate11 and 6-C-methyl and 6-C-(hydroxymethyl)analogues of V-acetylneuraminic acid (see Scheme 7.2).12... 

Deoxy-2-C- (hydroxymethyl) -2,21-0-i8opro-pylidene-D-eryihro-pentono- y-lactone... 

The structure of hamamelose as 2-C -(hydroxymethyl)-D-ribose has been established by the investigations of Freudenberg and of Schmidt. The studies of the latter author culminated in the chemical synthesis of the lactone which results from the oxidation of hamamelose. 

V. 3-C-(Hydroxymethyl)tetroses 1. 8-C-(IIydroxymethyl)-T>-glycero-aldotetrose (Apiose)... 

Finally, when L-sorbose (81) was treated with hydrogen cyanide, a branched-chain, sugar lactone was formed which was characterized by converting it into a diacetal.127 An X-ray structure determination of this material revealed it to be 2,21 5,6-di-0-isopropylidene-[2-C-(hy-droxymethyl)-L-gulono-l,4-lactone] (82). However, all subsequent efforts to prepare 82 resulted in the formation of 2,3 5,6-di-0-isopropyli-dene-2-C-(hydroxymethyl)-L-gulono-l,4-lactone (83). 

---