Stereoselective synthesis of (+)-cryptocarya diacetate by an iterative Prins cyclisation and reductive cleavage sequence

A highly stereoselective synthesis of (+)-cryptocarya diacetate is achieved through our recently developed strategy for the construction of 1,3-diols via Prins cyclisation. The route relies mainly on the reductive cleavage of allylic ethers, ozonolysis and Wittig olefination along with Prins cyclisation.     

Stereoselective synthesis of simplactone B via Prins cyclisation

The synthesis of simplactone B has been achieved through a series of nine steps in 85% overall yield using Prins cyclisation as the key step with high stereochemical control.     

Stereoselective synthesis of tarchonanthuslactone via the Prins cyclisation

The stereoselective total synthesis of tarchonanthuslactone, a polyketide natural product, has been achieved. The synthesis exploits the high stereochemical control in the Prins cyclisation along with ring closing metathesis (RCM) as a key step.     

The stereoselective total synthesis of xestodecalactone C and epi-sporostatin via the Prins cyclisation

Syntheses of xestodecalactone C and epi-sporostatin are described utilising Prins cyclisations, Mitsunobu reaction and intramolecular Friedel-Crafts acylation. The approach is convergent and highly stereoselective.     

Stereoselective syntheses of (−)-tetrahydrolipstatin via Prins cyclisations

Stereoselective syntheses of (−)-tetrahydrolipstatin have been achieved via two divergent approaches through Prins cyclisations as the key steps. PCC mediated oxidative cleavage, Frater alkylation, Keck allylation, Sharpless asymmetric epoxidation and allylic cleavage were the other key steps employed.     

Stereoselective total synthesis of decarestrictine-J via Ring Closing Metathesis (RCM)

Stereoselective total synthesis of decarestrictine-J, a polyketide natural product is described. The synthesis involves the Prins cyclisation and Ring Closing Metathesis (RCM) as key steps.     

Stereoselective synthesis of polyketide precursors containing an anti-1,3-diol system via a Prins cyclisation and reductive cleavage sequence

A new approach for the stereoselective synthesis of polyketide precursors containing anti-1,3-diol units flanked by a variety of alkyl branches and functional groups through a Prins cyclisation and reductive cleavage sequence is described.     

Stereoselective synthesis of anti-1,3-diol units via Prins cyclisation: application to the synthesis of (−)-sedamine

The scope of the Prins cyclisation, the higher stereoselective synthesis of multisubstituted tetrahydropyrans from aldehydes and homoallylic alcohols, is expanded. A new approach for the stereoselective synthesis of polyketide precursors containing anti-1,3-diols, flanked by a variety of alkyl branches and functional groups is described. The approach is successfully exploited for the synthesis of (−)-sedamine.     

A convergent route to β-hydroxy δ-lactones through Prins cyclisation as the key step: synthesis of (+)-prelactones B, C and V

Reactions of homoallylic alcohols with aldehydes in the presence of acid catalysts gave multisubstituted tetrahydropyrans with the creation of one to three new stereogenic centres in a single-pot process. The utility of this approach is extended to the enantioselective syntheses of (+)-prelactones B, C and V.     

Prins and RCM protocols for the synthesis of the pheromones of the giant white butterfly Idea leuconoe

The total syntheses of (6R)-6-[(2R)-2-hydroxyhexyl]tetrahydro-2H-2-pyranone and 7-hydroxy-5-dodecanolide are described utilizing a Prins reaction and ring closing metathesis reaction sequence.     

Total synthesis of (+/−)-diospongin A via Prins reaction

A straightforward synthesis of (+/−)-diospongin A starting from benzaldehyde is described. A Prins cyclization reaction to control the relative configuration of the three stereogenic centers and a Mitsunobu inversion represent the key steps of the approach.     

Application of Prins cyclization to the total synthesis of (+)-decytospolides A and B

(+)-Decytospolides A and B, natural products containing the tetrahydropyran skeleton, were synthesized via Prins cyclization as the key step.     

A concise stereoselective formal total synthesis of the cytotoxic macrolide (+)-Neopeltolide via Prins cyclization

A convergent and highly stereoselective formal total synthesis of the naturally occurring, cytotoxic 14-membered macrolide neopeltolide has been achieved via two Prins cyclizations.     

Reductive cyclisation of Morita-Baylis-Hillman adducts. A simple approach towards substituted hydrindanones and decalones

A connective synthesis of substituted hydrindanones and decalones can be accomplished based upon a novel approach involving two key-steps: a Morita-Baylis-Hillman condensation and an intramolecular reductive cyclisation using lithium in ammonia. Decalones, akin to the middle core of the clerodane family of natural products and bearing a quaternary carbon centre, can be readily assembled via this protocol.     

Total synthesis of cryptophycin-24 (arenastatin A) via Prins cyclization

A stereoselective synthesis of fragment A of cryptophycin is achieved utilizing the versatile Prins cyclization. Subsequently, the total synthesis of cryptophycin-24 (arenastatin A) has been accomplished by coupling it with the depsipeptide subunit.     

Direct synthesis of oxazolidin-2-ones from tert-butyl allylcarbamate via halo-induced cyclisation

A novel synthetic pathway towards the 2-oxazolidinone derivatives involving the halo-induced cyclisation of tert-butyl allyl(phenyl)carbamate was successfully developed. Various halogenating reagents were evaluated under different reaction conditions for the reaction optimisation. Interestingly, the synthetic route to 2-oxazolidinone derivatives containing one halogen atom in the aliphatic site or two halogen atoms including the extra halogen atom substituted in the aryl group at the para position, were thoroughly established for all chloro-, bromo- and iodo compounds. Either halo-unsubstituted-aryl oxazolidinone or p-halo-substituted-aryl oxazolidinone could be selectively produced by selecting the appropriate choices of halogenated reagents and reaction conditions e.g. reaction time and temperature. Toloxatone, a commercial antidepressant, was successfully synthesized by using this developed method.     

Total synthesis of basiliskamides A and B

[structure: see text] The first enantioselective synthesis of the polyketide antibiotics basiliskamides A and B, which exhibit potent in vivo activity against Candida albicans and Aspergillus fumigatus, has been achieved. Serial asymmetric crotylsilane and crotylboronate additions established the C7-C10 stereochemical tetrad. Takai iodoolefination and palladium-mediated cross-coupling were used to install the (Z,E)-vinyl acrylamide. Spectroscopic data is consistent with the assignment of the absolute configurations of the natural products as (7S,8S,9R,10S).     

Stereoselective synthesis of a 12-acetoxyazadiradione analogue

The synthesis of the 12-acetoxy enone 15 related to the limonoid azadiradione has been achieved in 12 steps (16% overall yield) starting from tricyclic diester 1. The key steps involve intramolecular 1,3-dipolar cycloaddition of a nitrile oxide and a Stille coupling reaction of a vinyl iodide with a stannylfuran.     

Stereoselective synthesis of cis-2,6-bis-hydroxyalkyl-tetrahydropyrans by the permanganate promoted oxidative cyclisation of 1,6-dienes

The first examples of permanganate promoted oxidative cyclisations of 1,6-dienes are described, providing exclusively cis-2,6-bis-hydroxyalkyl-tetrahydropyrans. In addition, good levels of asymmetric induction have been attained using dienoyl sultam substrates.     

A cationic cyclisation route to prenylated indole alkaloids: synthesis of malbrancheamide B and brevianamide B, and progress towards stephacidin A

The synthesis of the prenylated indole alkaloids, malbrancheamide B and brevianamide B have been accomplished, starting with a prenylated proline derivative created using the Seebach ‘self-reproduction of chirality’ method, and using a cationic cascade sequence as the key step to form late-stage bridged diketopiperazine intermediates.