Dioxoles anomeric effects

A detailed spectroscopic and theoretical study of the conformation of dioxolanes 1 has appeared <96T8275>, and a theoretical study has shown that the anomeric effect explains the non-planarity of 1,3-dioxole <96JA9850>. The tetraalkynyldioxolanone 2 has been prepared and its structure and reactivity studied <96HCA634>. Both enantiomers of the chiral glycolic acid equivalent 3 can be prepared from D-mannitol <96HCA1696>, and lipase-mediated kinetic... 

A theoretical study of the anomeric effect in 1,3-dioxole 9 involving interaction of the oxygen lone pairs with the C-O antibonding orbitals has provided an explanation for the unexpected nonplanarity observed for this compound <1996JA9850>. A combined theoretical and calorimetric study of the four benzodioxole compounds 10-13 has been used to obtain fundamental thermodynamic data for them <20040BC908>. The conformational preferences of 4,5-disubstituted-l,3-dioxolanes 14 have been analyzed computationally <1996T8275>. 

The anomeric effect is not limited to six-membered ring compounds. In five-membered rings the anomeric effect can affect both ring and substiment conformation. The 1,3-dioxole ring adopts a puckered conformation as a result of an anomeric effect. Similar effects are observed, although attenuated, in l,3-benzodioxoles. °... 

Of this group of molecules, the investigation of 1,3-benzodioxole (BZD) proved to be the most interesting due to the presence of the anomeric effect resulting from the -O-CH2-O- configuration. Previously we have studied 1,3-dioxole, 0CH20CH=CH2, and showed that his molecule was puckered with a barrier to planarity of 325 cm arising from the anomeric effect. The far-infrared... 

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