Stereoselective reduction of bicyclic ketals. A new, enantioselective synthesis of isolaurepinnacin and lauthisan skeletons

Kotsuki, Hiyoshizo; Ushio, Yasuyuki; Kadota, Isao; Ochi, Masamitsu

doi:10.1021/jo00282a037

Cited by 94 publications

(21 citation statements)

References 3 publications

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“…The configuration of the newly generated centres in 1c can be deduced by 1 H-NMR and NOE experiments. 6 The physical and spectroscopic data of 1c were identical with those reported. 6 In conclusion, we have developed a short approach to cis-disubstituted oxepanes with high enantiomeric excess using (S,S)-SalenMn III (Cl) as the catalyst.…”

Section: Introductionsupporting

confidence: 71%

“…6 The physical and spectroscopic data of 1c were identical with those reported. 6 In conclusion, we have developed a short approach to cis-disubstituted oxepanes with high enantiomeric excess using (S,S)-SalenMn III (Cl) as the catalyst. The R and S configurations of the cis ring can be manipulated simply by changing the catalyst in the resolution step.…”

Section: Introductionsupporting

confidence: 71%

“…5 Kotsuki et al reported the first total synthesis of (+)-isolaurepan via cis-selective reduction mediated by triethylsilane/TiCl 4 . 6 A few more groups have described its formal synthesis by different approaches. 7 Although there have been a number of reports on the stereoselective construction of racemic cis-2,7-disubstituted oxepanes, literature describing synthetic strategies for its non racemic derivatives is rather scarce.…”

Section: Introductionmentioning

confidence: 99%

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A total synthesis of (+)-isolaurepan

Tripathi

Kumar

2008

Tetrahedron Letters

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Section: Introductionsupporting

confidence: 71%

Section: Introductionsupporting

confidence: 71%

Section: Introductionmentioning

confidence: 99%

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A total synthesis of (+)-isolaurepan

Tripathi

Kumar

2008

Tetrahedron Letters

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“…Kotsuki et al [67] established a stereoselective reduction of bicyclic acetals 250 with Et 3 SiH in the presence of TiCl 4 producing a mixture of hydroxymethyl perhydroxyoxepins with cis-isomer 251a as a major one whereas, with DIBAL-H, the transisomer 251b is the major derivative. These are found as crucial intermediates of isolaurepinnacin 252 and lauthisan skeleton 253 (Scheme 54).…”

Section: Functionalization Of the Bicyclic Acetalmentioning

confidence: 99%

Advances in the Asymmetric Synthesis of Bridged and Fused Bicyclic Acetals

2018

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Fused and bridged bicyclic acetals are important structural motifs found in a diverse array of biologically active molecules. These conformationally rigid but stable structural segments are established within natural and unnatural compounds with biological importance. The structural and biological features of the molecules containing the fused and bridged ring systems have triggered a profound impact in the layout of newer synthetic methodologies and other designed entities. The interest in the development of efficient strategies to construct bicyclic scaffolds with fused and bridged bicyclic acetals in a stereocontrolled manner is substantial and challenging in the community of synthetic chemistry. The purpose of this review is to shed some light on the intriguing chemistry involved in the synthesis of conformationally constrained bridged and fused bicyclic acetals and its exploitation towards the synthesis of complex natural and unnatural molecules of biological and synthetic interest.

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“…We had previously used alane for the reduction of medium-ring methoxy-acetals; [6] howev- er, these conditions were deemed incompatible with the silyl-protecting groups. Independent reports from the groups of Yamamoto [27] and Kotsuki [28,29] suggested that diisobutylaluminium hydride would be a suitable reagent to effect the reduction of the acetals (AE )-19. Exposure of the acetals (AE)-19 to diisobutylaluminium hydride in dichloromethane resulted in the required reduction (with concomitant loss of the tert-butyldimethylsilyl protecting group) to deliver the The combination of a titanium Lewis acid and triethylsilane has been used for the reduction of bicyclic ketals.…”

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confidence: 99%

Synthesis of (+)‐Obtusenyne

Mak

Curtis

Payne

et al. 2008

Chemistry A European J

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An enantioselective synthesis of the halogenated medium-ring ether natural product (+)-obtusenyne is reported which uses the ring expansion of a seven-membered ketene acetal by means of a Claisen rearrangement to construct the core nine-membered oxygen heterocycle. The trans substituents across the ether linkage were established by using a transition-metal-catalyzed intramolecular hydrosilation reaction of an exo-cyclic enol ether. In addition, a formal synthesis of ent-obtusenyne from 2-deoxy-D-ribose is reported. A number of interesting points regarding the chemistry of medium-ring oxygen heterocycles are highlighted.

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Stereoselective reduction of bicyclic ketals. A new, enantioselective synthesis of isolaurepinnacin and lauthisan skeletons

Cited by 94 publications

References 3 publications

A total synthesis of (+)-isolaurepan

A total synthesis of (+)-isolaurepan

Advances in the Asymmetric Synthesis of Bridged and Fused Bicyclic Acetals

Synthesis of (+)‐Obtusenyne

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