中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | (-)-(2R)-2-acetyl-8-benzyloxy-5-methoxy-1,2,3,4-tetrahydronaphthalen-1-ol | 81504-96-3 | C20H22O4 | 326.392 |
中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | (-)-(2R,1'S)-5-benzyloxy-8-ethoxy-2-(1'-hydroxyethyl)-1,2,3,4-tetrahydronaphthalen-2-ol | 96291-98-4 | C21H26O4 | 342.435 |
—— | (-)-(2R)-2-acetyl-8-benzyloxy-5-methoxy-1,2,3,4-tetrahydronaphthalen-1-ol | 81504-96-3 | C20H22O4 | 326.392 |
—— | (-)-(2R)-2-acetyl-8-benzyloxy-2-(t-butyldimethylsilyloxy)-5-methoxy-1,2,3,4-tetrahydronaphthalene | 90744-28-8 | C26H36O4Si | 440.655 |
—— | (-)-(7R)-7-acetyl-7-(t-butyldimethylsilyloxy)-4-methoxy-5,6,7,8-tetrahydronaphthalen-1-ol | 90744-30-2 | C19H30O4Si | 350.53 |
The title dienones have been prepared from (-)-(2R,1′S)-8-benzyloxy-2-(1′-hydroxyethyl)-5-methoxy-1,2,3,4-tetrahydronaphthalen-2-ol, by a series of reactions in which the selective cleavage of an aryl methyl ether in the presence of an aryl ethyl ether plays a key role. This 10- step sequence proceeds in an overall yield of 55%, and chiral integrity is preserved throughout.
The title dienones (2) and (5) were prepared from the chiral alcohols (7a) and (7b) respectively. These key starting materials were in turn available from the reduction of 3-acetyl-5-benzyloxy-8-methoxy-1,2- dihydronaphthalene (6a) and 3-acetyl-8-benzyloxy-5-methoxy-1,2- dihydronaphthalene (6b) with lithium aluminium hydride modified with (—)-N- methylephedrine and N- ethylaniline . Chiral phase high-pressure liquid chromatography was used to analyse the enantioselectivity of these reductions which were shown to yield variable results depending upon the origin of the reducing agent.