TOTAL SYNTHESIS OF BAO-GONG-TENG-A, A NATURAL ANTIGLAUCOMA COMPOUND

被引：64

作者：

JUNG, ME ^{[1
]}

ZENG, LM ^{[1
]}

PENG, TS ^{[1
]}

ZENG, HY ^{[1
]}

LE, Y ^{[1
]}

SU, JY ^{[1
]}

机构：

[1] ZHONGSHAN UNIV, DEPT CHEM, CANTON, PEOPLES R CHINA

来源：

JOURNAL OF ORGANIC CHEMISTRY | 1992年 / 57卷 / 13期

关键词：

D O I：

10.1021/jo00039a005

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The total synthesis of Bao Gong Tong A (1), a novel natural product which shows antiglaucoma properties is described. The key step involves the highly regioselective and somewhat stereoselective 1,3-dipolar cycloaddition of acrylonitrile to N-benzyl-3-hydroxypyridinium bromide 2 to give the easily separable crystalline exo and endo diastereomers 3x and 3n in yields of 54% and 36%, respectively. Catalytic hydrogenation of the enone of 3x followed by reduction with sodium borohydride gave, via the saturated ketone 4, the exo alcohol 5x in 54% overall yield along with a small amount of the endo stereoisomer 5n. Protection of the alcohol followed by addition of methyl Grignard produced, after hydrolysis of the intermediate imine and the silyl other, the desired 6-exo-acetyl-8-benzyl-8-azabicyclo [3.2.1]octan-2-exo-ol (8) in 71 % yield. The synthesis of Bao Gong Teng A (1) was completed by first effecting a Baeyer-Villiger oxidation of 8 to give N-benzyl Bao Gong Teng A (9) (54% yield) and then cleaving the N-benzyl group by hydrogenolysis to produce 1 in 74% yield, thereby ending an eight-step synthesis of Bao Gong Teng A (1) in 8% overall yield from readily available starting materials.

引用

页码：3528 / 3530

页数：3

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