154706-44-2Relevant academic research and scientific papers
Synthesis of the natural products 3-hydroxymollugin and 3-methoxymollugin
Sastry, Mudiganti Naga Venkata,Claessens, Sven,Habonimana, Pascal,De Kimpe, Norbert
, p. 2274 - 2280 (2010)
(Figure Presented) 3-Hydroxymollugin 2 and 3-methoxymollugin 3 are cytotoxic compounds isolated as minor compounds from Pentas longiflora and Rubia cordifolia. Syntheses of 3-hydroxymollugin 2 and 3-methoxymollugin 3 were developed starting from easily available 3-bromomollugin 6. Surprisingly, it was found that the reaction of 3-bromomollugin 6 with sodium methoxide in methanol resulted in the formation of 3-methoxymollugin 3 and the ring-contracted methyl isopropenylfuromollugin 7. A mechanism for this ring contraction is proposed on the basis of a pericyclic retro oxa-6π ring-opening reaction. A second synthesis of 3-hydroxymollugin 2 was based on epoxidation of methyl 3-(3-methylbut-2-enyl)-l,4-naphthoquinone-2-carboxylate 17 and subsequent reduction of the quinone moiety, ring transformation, and DDQ oxidation. The latter oxidation process results in 3-hydroxymollugin 2 along with the rearranged furomollugin 4, which is a ring-contracted analogue of the natural product mollugin 1.
