provided substituted valerolactones (7) and (7′)via the [2,3]sigmatropic rearrangement of a nine-membered cyclic allylsulphonium ylide; the rearrangement product was converted to 5-alkylperhydrofuro[2,3-b]furan (12) by ozonolysis followed by acid treatment.
α-diazomalonate(处理6)用的Rh 2(OAc)4个立体选择性地提供取代的
戊内酯(7)和(7 ')通过的九元环状allylsulphonium叶立德的[2,3]σ重排; 通过
臭氧分解然后酸处理将重排产物转化为5-烷基全氢
呋喃[2,3- b ]
呋喃(12)。