Total syntheses of the sesquiterpenes β-corymbolol and corymbolone

Redefining the TGR5 Triterpenoid Binding Pocket at the C‐3 Position

“…Indeed, the allyl reactivity allows us to create multiple chemical modifications. Two series of derivatives were designed starting from 1 Dia 2 and are outlined in Scheme 2 (compounds 4-6) and Scheme 3 (compounds [8][9][10][11][12]. For the synthesis of derivatives 4-6 (Scheme 2), the initial step was the synthesis of ketone 3 by oxidation of betulinic acid, using Dess-Martin's reagent in dichloromethane.…”

“…[11] Finally, hydroboration of 8 Dia 2 with 9-borabicyclo[3.3.1]nonane (9-BBN) in THF followed by a oxidative work up afforded the alcohol 12. [12] New derivatives were also synthesized by modifying the lead compound 2 Dia 2, which bears the 2-methylallyl side chain (Scheme 4). Derivative 13 was synthesized from ketone 7 via Grignard reaction using 2-methylallyl magnesium chloride.…”

Profa. Dra. Helena M. C. Ferraz

“…Como principais contribuições científicas de sua carreira independente podemos destacar: o estudo de reações mediadas por sais de tálio(III), principalmente ciclizações eletrofílicas e contrações de anel [1][2][3][4][5][6] ; a investigação de reações de ciclofuncionalizações promovidas por reagentes de telúrio, de selênio e iodo, as quais permitiram a obtenção de uma série de heterociclos, sendo estes seus trabalhos mais citados na literatura [7][8][9][10][11] ; a síntese de lactonas de anel médio via reação de clivagem catalisada por tetróxido de rutênio [12][13][14] ; a síntese total de diversos produtos naturais utilizando, principalmente, as metodologias indicadas acima. Entre as moléculas sintetizadas podemos citar a frulanolida 15 , a corimbolona 16 , a mint-lactona 17 e o mutisiantol 18 .…”

Design and Synthesis of L‐Proline Derivatives as Enantioselective Organocatalysts for Synthesis of the (S)‐Wieland‐Miescher Ketone

“…( S )‐Wieland‐Miescher Ketone served as a starting material for a wide range of natural product synthesis, such as Penitrem D, Stachybotrylactam, Xylarenal A, β‐corymbolol, Oidiolatone B and so on (Figure ) . ( S )‐Wieland‐Miescher Ketone could be synthesized by Hajos‐Parrish‐Eder‐Sauer‐Wiechert reaction using the chiral organocatalyst (Figure ).…”