A facile two-step synthesis of methyl bis(2,2,2-trifluoroethyl)phosphonoacetate (Still–Gennari reagent) has been developed by exploiting Garegg–Samuelsson reaction conditions. Starting from trimethyl phosphonoacetate, Still–Gennari reagent was prepared in 94% yield via methyl 2-{bis[(trimethylsilyl)oxy]phosphoryl}acetate intermediate. This synthetic procedure was also used to prepare some kinds of Horner–Wadsworth–Emmons reagents and related compounds.

RRCs are potent oral care products for preventing halitosis via reducing CH SH production.

The synthesis of conjugated allenyl esters (tri-substituted allenes) was achieved by magnesium(II)-mediated Horner-Wadsworth-Emmons reaction of methyl bis(2,2,2-trifluoroethyl)phosphonoacetate with disubstituted ketenes. In addition, a novel access to α-fluorinated allenyl carboxamides (tetrasubstituted allenes) is presented.

A tandem thia-Michael/aldol reaction of allenyl esters and mercaptoacetaldehyde in the presence of triethylamine provided 2,3,4-trisubstituted tetrahydrothiophenes. Novel 2,3-disubstituted thiophenes were obtained in high yield by the subsequent dehydration of the 2,3,4-trisubstituted tetrahydrothiophenes using p-toluenesulfonic acid monohydrate as an effective catalyst.Thiophenes are an important class of heterocyclic compounds due to their wide range of biological activities 1-6 and applications to functional materials. [7][8][9] Therefore, many synthetic approaches for substituted thiophenes have been developed. [10][11][12] Recently we reported a novel tandem thia-Michael/Dieckmann condensation of allenyl esters with methyl mercaptoacetate for the regioselective synthesis of 2,3,5-trisubstituted thiophenes and 2,3,4-trisubstituted thiophenes. 13 As part of our ongoing effort towards the synthesis of polysubstituted thiophenes, we describe a tandem thia-Michael/aldol reaction of allenyl esters 1 14 with 1,4-dithiane-2,5-diol (2) for the construction of 2,3,4-trisubstituted tetrahydrothiophenes 3 via the ester enolates of thia-Michael adducts bearing a formyl group (Scheme 1).