Tetrazolylacetic acids

The syntheses of several 1-,2- and 5-tetrazolylacetic acids are described. Isomeric tetrazolylacetic esters can be separated by fractional distillation or crystallization. 5-Hydroxytetrazole reacts with ethyl bromoacetate in the presence of triethylamine to give 1,4-dicarbethoxymethyl-5-tetrazolone. The use of nuclear magnetic resonance spectroscopy for the assignment of structural isomers is discussed.

THE O-INSIDE CONFORMATION OF 1,3:2,4-DI-O-METHYLENE-L-THREITOL

1,3:2,4-Di-O-methylene-L-threitol was shown by measurement of its dipole moment and nuclear magnetic resonance spectrum to exist in the so-called O-inside conformation as would have been predicted by Mills.

THE ABSOLUTE CONFIGURATION OFdextro-1-DEUTERIOETHANOL

Reduction of 1,2-O-isopropylidene-3-O-benzyl-5-oxo-α-D-xylofuranose with lithium aluminum deuteride followed by removal of the isopropylidene and benzyl groups provided 5-deuterio-D-xylose. Nuclear magnetic resonance examination of the 5-deuterio-β-D-xylopyranose tetraacetate showed the isomer with the 5-carbon in the R-configuration (deuterium equatorial) to be present in 30% excess. The substance was degraded to 1-deuterioethanol, which possessed a dextrorotation of the magnitude expected and which necessarily possessed the R-configuration. This result confirmed the prediction made by Brewster (Tetrahedron Letters, 20, 23 (1959)).