Depending on the kind of R1 and R2, cyclic carbonates 1, in the presence of 10 mol% of Pd(PPh3)4 and 10 equiv of paraformaldehyde, selectively undergo three types of reaction: 1 (R1, R2 ≠ H) give dienes 3 exclusively; 1 (R1 = R2 = H and R1 ≠ H, R2 = H) furnish 6-vinyl-1,3-dioxanes 5 exclusively, while 1 (R1 = H, R2 ≠ H) give rise to 4-pentenyl formates 4 selectively (together with 3 as the minor products)
取决于R 1和R 2的种类,在10 mol%的Pd(PPh 3)4和10当量的多
聚甲醛的存在下,环状
碳酸酯1有选择地进行三种反应:1(R 1,R 2 ≠ H)只给二烯3个;1(R 1 = R 2 = H和R 1 ≠H,R 2 = H)仅提供6-
乙烯基-1,3-
二恶烷5,而1(R 1 = H,R 2 ≠H)产生4 -
戊烯基
甲酸酯4有选择地(与3个次要产品一起)。