Racemic (3S,4R/3R,4S)-faranal [(1a)+(1b)] has been synthesised by a convergent, stereospecific route which employed the addition of alkylcopper complexes to terminal acetylenes, to generate two trisubstituted double bonds, and a Diels–Alder reaction to establish the relative stereochemistry of the C-3, C-4 methyl groups. A diastereoisomeric mixture of faranals, enriched in the (3S,4S/3R,4R)-enantiomeric
外消旋的(3 S,4 R / 3 R,4 S)-
呋喃醛[(1a)+(1b)]已通过聚合的立体定向途径合成,该途径采用在末端
乙炔上添加烷基
铜配合物,生成两个三取代的双键和Diels-Alder反应建立C-3,C-4甲基的相对立体
化学。富含(3 S,4 S / 3 R,4 R)-对映异构体对[(1c)+(1d)]的法拉那尔的非对映异构混合物,是通过中间体二酯通过较短的路线合成的,该中间体由
巴豆酸乙酯的电
化学二聚。