Search results for "Dihydropyran"
showing 8 items of 8 documents
Stereoselective synthesis of the naturally occurring 2-pyranone dodoneine
2008
The first total synthesis of the naturally occurring dihydropyranone dodoneine is reported. Asymmetric allylation reactions were used for the stereoselective generation of the two stereogenic centers. The pyranone ring was created by ring-closing metathesis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Asymmetric Organocatalytic Michael Addition–Cyclization Cascade of Cyclopentane-1,2-dione with Substituted α,β-Unsaturated Aldehydes
2017
An asymmetric organocatalytic Michael addition–cyclization cascade reaction has been developed using cyclopentane-1,2-dione as a Michael donor and α,β-unsaturated aldehydes as Michael acceptors. Bicyclic hemiacetals were obtained in excellent yields and enantioselectivities. On the basis of the results, a one-pot reaction has been developed to obtain chiral 3-substituted cyclopentane-1,2-diones and substituted dihydropyrans in good yields and excellent enantioselectivity.
Stereoselective Syntheses of Naturally Occurring 5,6-Dihydropyran-2-ones
2007
The published syntheses of naturally occurring 5,6-dihydropyran-2-ones are reviewed. Figure options Download full-size image Download as PowerPoint slide
Synthesis and comparison of the antiinflammatory activity of manoalide and cacospongionolide B analogues.
1998
We have synthesized analogues of two naturally occurring antiinflammatory marine compounds, manoalide and cacospongionolide B, containing a pyranofuranone moiety which is considered the pharmacophoric group. The two compounds, and hence their analogues, differ in the presence or absence in the dihydropyran ring of an hemiacetal function which was considered essential to irreversibly inactivate phospholipase A 2 (PLA 2 ). The two series of compounds were tested for their inhibitory effects on secretory PLA 2 belonging to the groups I, II, and III, and the activities were found to be similar in both series, irrespective of the presence or absence of the additional hemiacetal function. In addi…
CCDC 684502: Experimental Crystal Structure Determination
2008
Related Article: F.Lehmann, D.Schollmeyer, S.Laufer|2008|Acta Crystallogr.,Sect.E:Struct.Rep.Online|64|o701|doi:10.1107/S160053680800487X
Synthesis of plagiochiline N from santonin.
2001
This article reports the transformation of O-acetylisophotosantonin, obtained by photochemical rearrangement of santonin, into plagiochiline N, an ent-2,3-secoaromadendrane isolated from Plagiochila ovalifolia. The synthesis was carried out in a sequence involving as the key steps (a) the substitution of the lactone moiety by a gem-dimethylcyclopropane ring through a synthetic intermediate having a C(6)-C(7) double bond and (b) the ozonolysis of the C(2)-C(3) bond followed by cyclization to the dihydropyran ring characteristic of plagiochiline N. Spectroscopic data of the synthetic product fully coincided with the reported data for the natural product.
ChemInform Abstract: Synthesis of Plagiochiline N from Santonin.
2010
This article reports the transformation of O-acetylisophotosantonin, obtained by photochemical rearrangement of santonin, into plagiochiline N, an ent-2,3-secoaromadendrane isolated from Plagiochila ovalifolia. The synthesis was carried out in a sequence involving as the key steps (a) the substitution of the lactone moiety by a gem-dimethylcyclopropane ring through a synthetic intermediate having a C(6)-C(7) double bond and (b) the ozonolysis of the C(2)-C(3) bond followed by cyclization to the dihydropyran ring characteristic of plagiochiline N. Spectroscopic data of the synthetic product fully coincided with the reported data for the natural product.