Sulphonic anhydrides and dimethylformamide convert ketones and aldehydes into enol sulphonates, which are generally relatively stable towards acids and bases but regenerate the carbonyl compounds by O-S bond cleavage on more vigorous treatment.
|Journal||Journal of the Chemical Society D: Chemical Communications|
|State||Published - 1969|
Bibliographical noteFunding Information:
We thank the Ministry of Commerce and Industry of Israel for their financial support. (Received, June 9th, 1969; Corn. 826.) Satisfactory analyses and Lr., n.m.r., and mass spectra were obtained for all new compounds reported. f The regeneration of carbonyl compounds from aliphatic enol sulphonates with formic acid was reported previously: ref. 1.S The pseudo-first-order rate constants for conversion of (3) (0.007~) into the 17j3-hydroxy-3-ketone in 50% MeOH and 56” were 3-17 x sec.-l and with H2S04 (0.4~)3.4 x sec.-l.with NaOH (1~)7 In this respect, the vinyl sulphonates (6) and (7) differ from the corresponding enol phosphates which, under base treatment, are converted into mono- and di-phenylacetylenes, respectively [J. Cymerman Craig and M. Moyle, J. Chem. SOL, 1963, 3712). P. E. Peterson and J. M. Indelicato, J. Amer. Chem. SOL, 1968,90, 6515; this report deals with preparation of double, substituted aliphatic enol toluene-p-sulphonates and bromobenzenesulphonates. For other methods see ref. 1of this paper. 2C. -4. BuntonandY. H. Frei, J. Chem. SOG.,1951, 1872. 3 For other examples of elimination reaction of enol sulphonates see I. Fleming and J. Harley-Mason, J. Chem. Soc., 1963,4771, 4778; E. J. I).Brown and J. Harley-Mason, J. Chem. SOG.(C),1966, 1390; G.Nakaminami, Bull. Chem. SOG.Japan, 1962.35, 1629.