Total Synthesis of (±)-Ginkgolide B

Crimmins, Michael T.; Pace, Jennifer M.; Nantermet, Philippe G.; Kim‐Meade, Agnes S.; Thomas, James B.; Watterson, Scott H.; Wagman, Allan S.

doi:10.1021/ja993013p

Cited by 51 publications

(25 citation statements)

References 21 publications

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“…The group of Crimmins reported on the use of the gauche effect of 1,2-dioxygen substituents to facilitate the ring closure (Scheme 1). [34] They also demonstrated the power of the RCM approach by establishing some very simple routes to chiral ether cyclization substrates. For example, an Evans aldol reaction of glycolate imides with acrolein led to the a,b-dihydroxy acid derivative 16.…”

mentioning

confidence: 99%

Synthesis of Medium-Sized Rings by the Ring-Closing Metathesis Reaction

Maier

2000

Angew. Chem. Int. Ed.

503

150

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Conformational constraints are the keys for the efficient synthesis of medium‐sized rings by ring‐closing olefin metathesis (RCM). While the RCM reaction has already proved itself in the synthesis of the larger macrocycles, like that found in epothilone, only recently has this reaction been increasingly used in the construction of eight‐ to ten‐membered carbo‐ and heterocycles. In the picture, a cyclopentane ring ensures the conformational constraints necessary for a successful cyclization.

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mentioning

confidence: 99%

Synthesis of Medium-Sized Rings by the Ring-Closing Metathesis Reaction

Maier

2000

Angew. Chem. Int. Ed.

503

150

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“…Enone 19 underwent intramolecular [2 þ 2]-photocycloaddition to a furan ring via conformation 19 0 in which both groups Et 3 SiO and CMe 3 at the stereogenic center can adopt a pseudoequatorial position (Scheme 6.8) [29]. In the typical scenario of a five-membered ring formation, the larger substituent at the stereogenic center resides frequently in the pseudoequatorial position of a chairlike conformation.…”

Section: [2 þ 2]-photocycloaddition Of Enones (Substrate Type A1)mentioning

confidence: 99%

Formation of a Four‐Membered Ring: From a Carbonyl‐Conjugated Alkene

Hehn

Müller

Bach

2009

Handbook of Synthetic Photochemistry

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“…[126] In a recently completed total synthesis of GB (2, Scheme 9), a photocycloaddition was again used as a key transformation. [127,128] First, 66 was treated with a zinc-copper homoenolate to give 67, which was then subjected to irradiation at 366 nm in hexanes, leading to 68 in high yield and excellent diastereoselectivity, establishing two quaternary centers and rings A, B, and C of GB (2) (Scheme 9). In three steps, lactone ring F was generated by hydrolysis of the triethylsilyl ether, mesylation of the resulting alcohol, and treatment with pyridinium p-toluenesulfonic acid (PPTS) to give 69 in 63 % overall yield.…”

Section: Ginkgolidesmentioning

confidence: 99%

Chemistry and Biology of Terpene Trilactones fromGinkgo Biloba

2004

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Ginkgo biloba, the ginkgo tree, is the oldest living tree, with a long history of use in traditional Chinese medicine. In recent years, the leaf extracts have been widely sold as phytomedicine in Europe and as a dietary supplement worldwide. Effects of Ginkgo biloba extracts have been postulated to include improvement of memory, increased blood circulation, as well as beneficial effects to sufferers of Alzheimer's disease. The most unique components of the extracts are the terpene trilactones, that is, ginkgolides and bilobalide. These structurally complex molecules have been attractive targets for total synthesis. Terpene trilactones are believed to be partly responsible for the neuromodulatory properties of Ginkgo biloba extracts, and several biological effects of the terpene trilactones have been discovered in recent years, making them attractive pharmacological tools that could provide insight into the effects of Ginkgo biloba extracts.

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Total Synthesis of (±)-Ginkgolide B

Cited by 51 publications

References 21 publications

Synthesis of Medium-Sized Rings by the Ring-Closing Metathesis Reaction

Synthesis of Medium-Sized Rings by the Ring-Closing Metathesis Reaction

Formation of a Four‐Membered Ring: From a Carbonyl‐Conjugated Alkene

Chemistry and Biology of Terpene Trilactones fromGinkgo Biloba

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