Scheme 3. Synthesis of the geranyl derivative 4g.Cp= cyclopentadienyl, pyr = pyridine, Ts = 4-toluenesulfonyl.Scheme4. Enantioselective S N 2s ubstitution reaction leading to the trail pheromone(+ +)-faranal (9). Reagents and conditions:i ) t BuLi, inverse addition, diethyl ether/hexane (2:3), À100 8 8C, 1min; ii)CuBr·P(OEt) 3 ,d iethyl ether/hexane(2:3), À100 8 8C, 1min;i ii)solvent switch to THF at À50 8 8C. DMAP = 4-dimethylaminopyridine.

The cytochalasans are a large family of polyketide natural products with potent bioactivities. Amongst them, the aspochalasins show particularly intricate and fascinating structures. To gain insight into their structural diversity and innate reactivity, we have developed a rapid synthesis of aspochalasin D, the central member of the family. It proceeded in 13 steps starting from divinyl carbinol and utilized a high pressure Diels-Alder reaction that features high regio- and stereoselectivity. So far, our work has culminated in a biomimetic synthesis of aspergillin PZ, an intricate pentacyclic aspochalasan.

From both structural and functional perspectives, the large family of daphnane diterpene orthoesters (DDOs) represent a truly remarkable class of natural products. As potent lead compounds for the treatment of pain, neurodegeneration, HIV/ AIDS, and cancer, their medicinal potential continues to be heavily investigated, yet synthetic routes to DDO natural products remain rare. Herein we report a distinct approach to this class of complex diterpenes, highlighted by a 15-step total synthesis of the flagship DDO, resiniferatoxin.

Chirale sekundäre Alkylkupferverbindungen wurden aus chiralen sekundären Alkyliodiden durch einen I/Li‐Austausch, gefolgt von einer retentiven Transmetallierung mit CuBr⋅P(OEt)3, hergestellt. Durch Wechseln des Lösungsmittels zu THF wird die konfigurative Stabilität der Kupferverbindungen signifikant verbessert und macht diese für regioselektive allylische Substitutionen brauchbar. Diese optisch angereicherten Kupferreagentien gingen SN2‐Substitutionen mit Allylbromiden (bis zu >99 % SN2‐Regioselektivität) ein. Versetzen mit ZnCl2 und die Verwendung von chiralen Allylphosphaten ermöglicht es, die Regioselektivität hin zu SN2′‐Substitutionen zu verschieben (bis zu >99 % SN2′‐Regioselektivität), sowie die Durchführung von äußerst selektiven anti‐SN2′‐Substitutionen mit kompletter Kontrolle von zwei nebeneinanderliegenden Stereozentren. Diese Methode wurde in der Naturstoffsynthese von drei Ameisenpheromonen – (+)‐Lasiol, (+)‐13‐Norfaranal und (+)‐Faranal (dr bis zu 98:2, 99 % ee) – angewendet.

The cytochalasans are al arge family of polyketide natural products with potent bioactivities.A mongst them, the aspochalasins show particularly intricate and fascinating structures.T og ain insight into their structural diversity and innate reactivity,w eh ave developed ar apid synthesis of aspochalasin D, the central member of the family.Itproceeded in 13 steps starting from divinyl carbinol and utilized ah igh pressure Diels-Alder reaction that features high regio-and stereoselectivity.Sofar,our work has culminated in abiomimetic synthesis of aspergillin PZ, an intricate pentacyclic aspochalasan.