The reaction of lupane (1) with chromium oxide gave lup-2-en-1-one (3), lupan-12-one (2), lupan-16-one (isolated after hydride reduction as lupan-16α-ol (4)), and lup-18-en-21-one (5) in low yields. The same oxidation of 3β,28-dimethoxylupane (11) afforded no products of functionalization in non-activated positions; only products of oxidation of the 3β-methoxy group and of the oxidation cleavage of the A ring were obtained, viz. 28-methoxylupan-3β-ol formate (12), 28-methoxylupan-3-one (14), and 28-methoxy-2-norlupane-1,3-dioic anhydride (13). The structure of the compounds obtained was confirmed by their 1H NMR, 13C NMR, and mass spectra. The lupan-12-one (2) prepared is not identical with clerodone, whose isolation from Clerodendron infortunatum BHAT. was described in 1965 and to which the structure of lupan-12-one was then ascribed.
卢班烷(
1)与
氧化铬反应,得到低收率的卢-2-
烯-1-
酮(
3),卢班-12-
酮(
2),卢班-16-
酮(通过
氢化还原后分离为卢班-16α-醇(
4))和卢-18-
烯-21-
酮(
5)。同样的,对3β,28-二甲
氧基卢班(
11)进行
氧化,未在非活化位置上产生任何官能团化产物;只得到了3β-甲
氧基基团的
氧化产物和A环
氧化裂解产物,即28-甲
氧基卢班-3β-醇
甲酸酯(
12),28-甲
氧基卢班-3-
酮(
14)和28-甲
氧基-2-诺卢班-1,3-二酸酐(
13)。通过它们的
1H NMR,
13C NMR和质谱证实了所得化合物的结构。制备的卢班-12-
酮(
2)与克勒罗东不同,后者从
Clerodendron infortunatum BHAT中分离出来并在1965年进行了描述,当时将其归属为卢班-12-
酮的结构。