| 摘要 |
The invention comprises compounds of the general formulae <FORM:1028570/C2/1> <FORM:1028570/C2/2> wherein R is a hydrogen atom or an alkyl or alkanoyl radical; X is a carbonyl radical, or a radical of the general formula <FORM:1028570/C2/3> wherein R1 can be a hydrogen atom or an alkyl, or alkanoyl radical, and R11 is a hydrogen atom or an alkyl, alkenyl or alkynyl radical, and the wavy lines indicate the alternative "a " or "b " configurations; M is a hydrogen, ammonium or alkali metal cation; n is a positive integer less than 3; and wherein the aliphatic hydrocarbon radicals contain less than 8 carbon atoms, and the alkanoyl radicals 2-7 carbon atoms inclusive. These compounds are obtained by the reduction of an aldehydo-acid or its salt of the formula <FORM:1028570/C2/4> wherein M is as defined above, R1 is an alkyl or alkanoyl radical; and m is 0 or 1, to obtain a D-homo lactone or the corresponding hydroxy acid. Treatment of the 3-alkoxy or 3-alkanoyloxy compounds with alkali gives the 3-hydroxy compounds which may be re-esterified or reetherified. Contacting the lactones with an organic metallic reagent produces the corresponding lactols and their corresponding open-chain tautomeric forms. Lactols are also obtained by reducing the corresponding lactones. The 17- and 17a-hydroxy groups may be etherified, while esterification of the 3,17-dihydroxy compounds yields the corresponding 3,17-dialkanoates. |
