中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | 3-formyl-1-hydroxy-4-methoxy-2-(2'-methylprop-2'-enyl)anthraquinone | 254896-22-5 | C20H16O5 | 336.344 |
—— | 2-dimethoxymethyl-1-methoxy-4-(2'-methylprop-2'-enyloxy)anthraquinone | 254896-04-3 | C22H22O6 | 382.413 |
—— | 1-methoxy-4-hydroxy-9,10-dioxo-9,10-dihydroanthracene-2-carbaldehyde | 126308-22-3 | C16H10O5 | 282.252 |
—— | 2-formyl-1-methoxy-4-(2'-methylprop-2'-enyloxy)anthraquinone | 254896-03-2 | C20H16O5 | 336.344 |
The methylidene tetracycle (2) has been synthesized in 11 steps from quinizarin (5) in an overall yield of 38% by using a highly ecient selective dihydroxylation step and an intramolecular ene cyclization. Also prepared with the selective dihydroxylation methodology were the silyloxy alkene (3) and the 6-demethoxy alkene (4). A mixture (1 : 2) of the (E)- and (Z)-isomers of the ethylidene compound (6) has been prepared by similar methods. The products resulting from the reactions of AD-mix-α and AD-mix-β on the alkenes (1)–(3) and (6) have been investigated and their stereochemistries assigned by using 1 H n.m.r. and NOESY experiments, and molecular modelling of acetonide derivatives. An X-ray crystal structure of the acetate (64) has confirmed the relative stereochemical assignments.