Thiones 2(′), 4(′) and 3(′) are readily prepared from title compounds. Bis-olefinations of 3 with Akiba's reagents W or H afford 8 which can cyclize into 9 upon acid areatment. (i-PrO)3P mediated coupling of 4 with 5′ affords 7 whose formolysis in 10 and bis-olefination with W or H yields target compound 1. The π-donor ability and stability of 8 and 1 are discussed.
由标题化合物易于制备亚
硫醚2('),4(')和3(')。的双烯化反应3与秋叶的试剂W¯¯或ħ得到8,其可环化到9在酸areatment。(我-Pro)3 P间接的耦合4与5'得到7,其在formolysis 10和双烯与W¯¯或ħ得到目标化合物1。8和1的π供体能力和稳定性 讨论。