Rg. Kostyanovsky et al., AUTOASSEMBLY OF CAGE STRUCTURES .7. LACTONIZATION OF METHYLENE-BIS-TARTRONATES AND METHYLENE-BIS-HYDROXYMETHYLMALONATES, Russian chemical bulletin, 43(11), 1994, pp. 1889-1894
Methylene-bis-tartronates and methylene-bis-hydroxymethylmalonates for
m monolactones where the CO(2)R and OH (or CH2OH) groups are known to
be cis-oriented. However, attempts to prepare the corresponding dilact
ones failed due to the unsufficient proximity of these functional grou
ps. The results have been confirmed by NMR spectra.