| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1988: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1987: ¥1,500,000 (Direct Cost: ¥1,500,000)
|
|---|
| Research Abstract |
In this project, new synthesis of oxygen heterocycles, which are expected to exhibit biological activities, was studied.
In chapter 1, synthesis of -diethoxyphosphinyl- -butenolides and their application to the general synthesis of -lactones with , -fused ring systems were described. Cyclosarkomycin and its analogues were easily and efficiently synthesized in few steps from the -phosphono-butenolide and diethly acetal of 2-(formylalkyl)-1,3-dithianes.
In chapter 2, new synthesis of -methylene lactones was described. A various kinds of -diethoxyphosphinyl- , -unsaturated carboxylic acids, which were prepared from diethoxy-phosphinylacetic acid and allylic bromides, easily underwent iodo- and selenolactonization to produce -phosphono-iodo and -selenolactones. The Wittig-Horner reaction of the - phosphonolactones with paraformaldehyde provided -methylene- -lactones in good yields. This synthetic methodology was successfully applied to the synthesis of frullanolide, which is a naturally occurring compound.
In chapter 3, new synthesis of 3,4-fused coumarins was described. The Witting-Horner reaction of o-hydroxybenzaldehydes with -diethoxyphosphinyl- -butyro-lactone gave 3-(hydroxyethyl)-coumarins in quantitative yields. The coumarins were easily converted into 3-vinylcoumarins by treatment with DBU. The Diels-Alder reaction of the vinylcoumarins with various dienophiles gave functionalized 3,4-fused coumarins.
|
