BUXUS ALKALOIDS .13. A SYNTHETIC APPROACH TO 9(10-]19) ABEO-PREGNANE SYSTEM
BUXUS ALKALOIDS .13. A SYNTHETIC APPROACH TO 9(10-]19) ABEO-PREGNANE SYSTEM
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DOI：
10.1021/ja01000a060
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发表时间：
1967-01-01
影响因子：
15
通讯作者：
BY, AW
中科院分区：
文献类型：
--
作者：
KUPCHAN, SM;ABUSHANAB, E;BY, AW
当9 S，19-环-5 α-癸烷-3，11，20-三酮-3，20-二乙烯缩酮（V）进行Wolff-Kishner还原的Huang-Minlon修饰时，没有得到预期的11-脱氧化合物。相反，分离并表征了两种结晶C-10差向异构体，9（10- 19）硫代-Δ 9（α 1）-5 α，10 α 1）-异戊烯-3，20-二酮3，20-二乙烯缩酮（IX）和9（10- 19）硫代-Δ 8 α 1）-5 α，10 α 1）-异戊烯-3，20-二酮3，20-二乙烯缩酮（X）。用三氟化硼醚合物对二缩酮进行选择性缩酮水解，得到相应的C-20酮XI和XII。二缩酮的催化氢化得到二氢衍生物XIII和XIV，水解得到相应的二氢单酮XV和XVI以及二氢二酮XVII和XVIII。通过测定XV-XVIII的旋光色散确定了IX和X的构型。讨论了B环扩环反应对黄杨属生物碱两种主要结构类型的化学联系和9（10-*-19）<$6-EO-二十四烷系列生物碱生物成因的潜在意义。
When 9S, 19-cyclo-5a-pregnane-3, ll, 20-trione 3, 20-diethylene ketal (V) was subjected to the Huang-Minlon modification of the Wolff-Kishner reduction, the expected 11-deoxo compound was not obtained. In-stead, two crystalline C-10 epimers, 9 (10-> 19) ti0eo-A9 (u;-5a, 10d-pregnene-3, 20-dione 3, 20-diethylene ketal (IX) and 9 (10-»-19) a¿> eo-A8ai)-5a, 10a:-pregnene-3, 20-dione 3, 20-diethylene ketal (X), were isolated and characterized. Selective ketal hydrolysis of the diketals with boron trifluoride etherate yielded the respective C-20 ketones, XI and XII. Catalytic hydrogenation of the diketals yielded the dihydro derivatives, XIII and XIV, and hydrolysis afforded the respective dihydro monoketones, XV and XVI, and dihydro diketones, XVII and XVIII. The con-figurations of IX and X were determined by optical rotatory dispersion measurements of XV-XVIII. The potential significance of the ring B enlargement reaction for the chemical interrelation of the two principal structural types of the Buxus alkaloids and for the biogenesis of alkaloids of the 9 (10—*-19)¿¡ 6eo-pregnane series are discussed.