M. Muller et al., Stereoselective total syntheses of atrochrysone, torosachrysone and related 3,4-dihydroanthracen-1(2H)-ones, J CHEM S P1, (15), 2000, pp. 2483-2489
The total synthesis of the pre-anthraquinones atrochrysone 1 and torosachry
sone 2 in both enantiomeric forms is described. The synthesis relies on the
regioselective Tebbe methylenation of a chiral diester followed by an intr
amolecular enol ether acylation with N-triflyl-4-(dimethylamino)pyridinium
triflate. The resulting 3-methoxycyclohex-2-enone 9 is condensed with suita
ble orsellinic acid derivatives to yield after deprotection the optically a
ctive 3,4-dihydroanthracen-1(2H)-ones 1 and 2. This flexible approach can b
e used for the synthesis of C-13-labelled compounds and should provide acce
ss to a series of analogues.