Total Synthesis of Adunctin B

Total synthesis of (±)-adunctin B, a natural product isolated from <i>Piper aduncum</i> (Piperaceae), has been achieved using two different strategies, in seven and three steps. The efficient approach features highly atom economical and diastereoselective Friedel–Crafts acylation, alkylation reaction and palladium catalyzed Wacker type oxidative cyclization

Enantioselective Total Syntheses of (+)-Hostmanin A, (−)-Linderol A, (+)-Methyllinderatin and Structural Reassignment of Adunctin E

A one-step protocol has been developed for the enantioselective synthesis of hexahydrodibenzofuran derivatives using a modified Friedel–Crafts reaction. The developed method was applied to the synthesis of a series of natural products including (+)-hostmanin A, (+)-methyllinderatin, and (−)-linderol A. The synthetic and spectroscopic data investigations led to the structural reassignment of natural product adunctin E, which was further confirmed by single-crystal X-ray analysis

Remarkable Switch of Regioselectivity in Diels–Alder Reaction: Divergent Total Synthesis of Borreverine, Caulindoles, and Flinderoles

Switchable reaction patterns of dimerization of indole substituted butadienes via a Lewis acid and thermal activation are reported. While under acidic conditions dimerization occurred around the internal double bond of the dienophile, a complete switch of regioselectivity was observed under thermal conditions, where dimerization occurred around the terminal double bond of the dienophile. This switch of regioselectivity was further exploited for the divergent total synthesis of structurally diverse indole alkaloid natural products

Biomimetic Total Syntheses of Borreverine and Flinderole Alkaloids

Dimeric indole alkaloids represent a structurally unique class of natural products having interesting biological activities. Recently, we reported the first total synthesis of flinderoles B and C, structurally unique and potent antimalarial natural products. Central to the design of the approach and by virtue of a one-pot, acid-catalyzed dimerization reaction, the route also provided total synthesis of the borreverine class of natural products. This full account details the progress of efforts that culminated in the protecting-group-free, six-step total synthesis of all of the flindersia alkaloids: dimethylisoborreverine, isoborreverine, flinderoles A–C, and their analogues. A biomimetic approach featuring a scalable and catalytic formal [3 + 2] cycloaddition and Diels–Alder reaction is outlined in detail. On the basis of the experimental observations, a detailed mechanism has been proposed for the dimerization of tertiary alcohol <b>28</b>

Remarkable Switch of Regioselectivity in Diels–Alder Reaction: Divergent Total Synthesis of Borreverine, Caulindoles, and Flinderoles

Switchable reaction patterns of dimerization of indole substituted butadienes via a Lewis acid and thermal activation are reported. While under acidic conditions dimerization occurred around the internal double bond of the dienophile, a complete switch of regioselectivity was observed under thermal conditions, where dimerization occurred around the terminal double bond of the dienophile. This switch of regioselectivity was further exploited for the divergent total synthesis of structurally diverse indole alkaloid natural products

Remarkable Switch of Regioselectivity in Diels–Alder Reaction: Divergent Total Synthesis of Borreverine, Caulindoles, and Flinderoles

Switchable reaction patterns of dimerization of indole substituted butadienes via a Lewis acid and thermal activation are reported. While under acidic conditions dimerization occurred around the internal double bond of the dienophile, a complete switch of regioselectivity was observed under thermal conditions, where dimerization occurred around the terminal double bond of the dienophile. This switch of regioselectivity was further exploited for the divergent total synthesis of structurally diverse indole alkaloid natural products