Derivatives of N,N'-bis[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]ethanediamide

compound, [(hoch2)3cnhc(o)]2 (1), obtained from (hoch2)3cnh2 and etoc(o)c(o)oet, reacts with aryl aldehydes, archo, to give the symmetric bis-alkylidene derivatives, n,n'-bis(2-ar-5-roch 2-1,3-dioxan-5-yl)ethanediamides 3 (ar = ph, p-mec6h4 or p-meoc6h4, r = h). a similar reaction with me2co produced n'-bis(2,2-dimethyl-5-hydroxymethyl-1,3-dioxan-5-yl)ethanediamide (2). while three stereoisomers, (z,z)-, (z,e)- and (e,e)-3 (ar = ph, r = h), were formed from 1 and phcho, only (z,z)-3 (ar = p-mec6h4 or p-meoc6h4, r = h) was isolated from archo (ar = p-mec6h4 or p-meoc6h4) [the z conformations in the solid state and in solution have equatorial-aryl, equatorial-hoch2 and axial-amido groups: e forms have equatorial-aryl, equatorial-amido and axial-hoch2 groups]. a 1:1 mixture of (z,z)-:(e,e)-3 (ar = ph, r = h) co-crystallises. molecular mechanics calculations have been carried out on the conformation energies of (z,z)-and (e,e)-3 (ar = ph, r = h) and 1 and support the crystallographic and spectral findings. the stereoisomer, (z,z)-3 (ar = ph, r = h), is more reactive in alkylation reactions than the (e,e)-form: only (z,z)-3 (ar = ph, r = ph3snch2) was isolated from the reaction of a mixture of (z,z)- and (e,e)-3 (ar = ph, r = h) with ph3snch2i. from the reaction of excess allyl bromide with a 1:1 mixture of (z,z)- and (e,e)-3 (ar = ph, r = h), a 4:3 mixture of (z,z)- and (e,e)-3 (ar = ph, r = h2c=chch2) was isolated. oxymercuriation of (z,z)-3 (ar = ph, r = h2c=chch2) with hg(oac)2 in meoh, followed by anion exchange using nacl, produced the single stereoisomer, {n-(z)-[[(r2)-5-(3-chloromercuri-2-methoxypropyl)oxymethyl]-2-phenyl-1,3 -dioxan-5-yl]}{n'-(z)-[[(s 2)-5-(3-chloromercuri-2-methoxypropyl)oxymethyl]-2-phenyl-1,3-dioxan -5-yl]}ethanediamide (4), characterised by x-ray crystallography.