An expedient synthesis of 5-n-alkylresorcinols and novel 5-n-alkylresorcinol haptens

• Kirsti Parikka and
• Kristiina Wähälä

Beilstein J. Org. Chem. 2009, 5, No. 22, doi:10.3762/bjoc.5.22

• few papers have reported Wittig reactions in water without an organic solvent, although the related Horner-Wadsworth-Emmons reactions, using ester enolate type stabilized phosphonate ylids, have often been conducted in aqueous solutions [29]. The existing cases have mostly been targeted for the

Synthesis and redox behavior of new ferrocene- π-extended- dithiafulvalenes: An approach for anticipated organic conductors

• Abdelwareth A. O. Sarhan,
• Omar F. Mohammed and
• Taeko Izumi

Beilstein J. Org. Chem. 2009, 5, No. 6, doi:10.3762/bjoc.5.6

• derivatives 5a and 5b were synthesized cleanly and in high yields according to previously reported methods [12][13][15]. The 1,3-benzodithiole-2-phosphonate 6 was obtained in relatively high yield as described previously in literature [14][28][29]. Reaction of ferrocene-1,1′-dicarboxaldehyde (5a) or 1,1

• ′-diacetylferrocene (5b) with 1,3-benzodithiole-2-phosphonate (6) in dry THF in the presence of n-BuLi at −78 °C following the Wittig–Horner reaction method afforded the corresponding 1,1′-bis[(1,3-dithiol-2-ylidene)methyl]ferrocenes 7a and 7b in good yields (Scheme 1). The 1,1′-bis(1,3-dithiafulvalene)ferrocene 7a

• ]. However, upon reaction of the diacylferrocene 5c with the 1,3-benzodithiole-2-phosphonate 6 using a slight modification of the Wittig–Horner procedures, by carrying out the reaction at −20 to 0 °C and subsequently purifying by column chromatography using chloroform/hexane mixture, the 1,1′-bis(1,3-DTF)Fc

Unexpected degradation of the bisphosphonate P-C-P bridge under mild conditions

• Petri A. Turhanen and
• Jouko J. Vepsäläinen

Beilstein J. Org. Chem. 2008, 4, No. 7, doi:10.1186/1860-5397-4-7

• reaction conditions in two of the prepared etidronate derivatives. Earlier, Szymczak et. al. [24] have described the formation of H-phosphonate (also known as phosphite) and phosphate components from a phosphonate-phosphate compound (same kind of structure as 8 in Scheme 1) either in CH3CN/Et3N/H2O (v/v

• ) or phosphate buffer, pH 7.4 at 37 °C. Szajnman et. al. [25] has reported loss of two molecules of phosphite in tetraethyl oxirane-2,2-diylbis(phosphonate); however the kind of degradation which we will discuss in this paper has not been previously reported. Results and Discussion As mentioned in the

• ) partial transesterification of bisphosphonate 1a before degradation of P-C-P bridge, 2) partial esterification of phosphonate group after the carbonate groups (R3) decomposition from compound 1a (this is proposed to occur rapidly after the addition of 40% NaOH) and before the degradation of P-C-P bridge

Synthesis of novel (1-alkanoyloxy- 4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives

• Petri A. Turhanen and
• Jouko J. Vepsäläinen

Beilstein J. Org. Chem. 2006, 2, No. 2, doi:10.1186/1860-5397-2-2

• have also recently described the method for the preparation of (1-alkoxycarbonyloxyethylidene)-1,1-bisphosphonic acid derivatives [20] and novel fatty acid derivatives of etidronate [21] which may represent prodrugs of etidronate. In the case of etidronic acid, we have shown that simple phosphonate