
TY  - JOUR
A1  - Cambie, Richard C. 
A1  - Clark, Russell B. 
A1  - Rutledge, Peter S. 
A1  - Rustenhoven, J. J. 
T1  - Experiments Directed Towards the Synthesis of Anthracyclinones. XXXVI Asymmetric Dihydroxylations of Alkylidene Anthracyclinones
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1999
VL  - 52
IS  - 8
SP  - 781
EP  - 800
KW  - 
UR  - https://doi.org/10.1071/CH99014 
N2  - 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-&#945; and AD-mix-&#946; on the alkenes (1)&#8211;(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. 
ER  -

