Regiopspecific cyclization of the acetal (4g), derived in 5 steps from 2′-benzyloxyacetophenone (3a), gave the pyrone (6a), which was easily converted into 2-methyl-5H-pyrano[3,2-c][1]benzopyran-4-one (1b), the basicskeleton in citromycetin (1a).
乙醛(4g)的区域特异性环化,由2'-苄氧基苯乙酮(3a)分5步产生,得到了吡喃酮(6a),该吡喃酮易于转化为2-甲基-5 H-吡喃并[3,2- c ] [ 1]苯并吡喃-4-酮(1b),是柠檬霉素的基本骨架(1a)。
Yamauchi, Masashige; Katayama, Sadamu; Nakashita, Yoshihiko, Journal of the Chemical Society. Perkin transactions I, 1985, p. 183 - 186