STEREOCHEMISTRY OF ARYLGLYCEROL BETA-ARYL ETHERS - CRYSTAL-STRUCTURE OF ERYTHRO-3-HYDROXY-3-(4-METHOXYPHENYL)-2-PHENOXYPROPANOIC ACID

The threo and erythro forms of 3-hydroxy-3-(4-methoxyphenyl)-2-phenoxypropanoic acid have been synthesized. Reduction with borane-dimethyl sulfide complex gave the threo and erythro forms of the lignin model 2-phenoxy-1-phenyl-1,3-propanediol. The steric assignments were derived from a crystal structure determination of erythro-3-hydroxy-3-(4-methoxyphenyl)-2-phenoxypropanoic acid by single-crystal X-ray diffraction methods. The compound crystallizes as colourless prisms in the triclinic space group P1BAR with a = 9.785(1), b = 13.369(2), c = 5.768(1) angstrom, alpha = 101.74(1), beta = 92.43(1), gamma = 102.77(1)-degrees, V = 717.4(1) angstrom3 and Z = 2. A final R-value of 0.035 was obtained.