900509-67-3Relevant academic research and scientific papers
Synthesis of 6,6-bisbenzannulated spiroketals related to the rubromycins using a double intramolecular hetero-Michael addition (DIHMA)
Choi, Peter J.,Rathwell, Dominea C.K.,Brimble, Margaret A.
scheme or table, p. 3245 - 3248 (2009/08/17)
The synthesis of a series of 6,6-bisbenzannulated spiroketals using a novel microwave-assisted DIHMA approach is reported. Coupling of an aryl acetylene and an aryl aldehyde via acetylide anion addition resulted in the formation of an alkynol which was followed by oxidation to the desired ynone. Spirocyclization using the DIHMA protocol afforded the desired bisbenzannulated spiroketal in good yield.
A facile synthesis of fused aromatic spiroacetals based on the 3,4,3′,4′-tetrahydro-2,2′-spirobis(2H-1-benzopyran) skeleton
Brimble, Margaret A.,Flowers, Christopher L.,Trzoss, Michael,Tsang, Kit Y.
, p. 5883 - 5896 (2007/10/03)
The facile synthesis of a series of aromatic 6,6-spiroacetals based on the parent 3,4,3′,4′-tetrahydro-2,2′-spirobis(2H-1-benzopyran) heterocyclic system is reported. Key steps included the use of a Sonogashira coupling for the synthesis of an aryl acetylene that was coupled to an aryl aldehyde to form a propargyl alcohol intermediate. Hydrogenation of the alkynol followed by oxidation produced a masked dihydroxy ketone that upon treatment with trimethylsilyl bromide underwent deprotection and cyclisation to the fused aromatic spiroacetal.
