A 12-membered to a strained 11-membered ring: first stereoselective total synthesis of (-)-asteriscunolide C

The first stereoselective total synthesis of (-)-asteriscunolide C has been accomplished in 12 steps in a 16% overall yield. The key step is the conversion of a 12-membered to a strained 11-membered ring with one Z- and two E-double bonds employing a late stage ring-closing metathesis

A Dotz benzannulation route to the enantioselective synthesis of (-)- and (+)-juglomycin A

Two synthetic routes based on a Dotz benzannulation toward the enantioselective synthesis of naphthoquinone antibiotics (-)- and (+)-juglomycin A are described. The stereoinducing step is based on asymmetric dihydroxylation. The syntheses are completed in seven to eight steps from Fischer carbene 12. (C) 2011 Elsevier Ltd. All rights reserved

Stereoselective synthesis of (-)-1-epi-ventiloquinone L and (+)-ventiloquinone L, the monomeric unit of cardinalin 3

A stereoselective synthesis of (-)-1-epi-ventiloquinone L and (+)-ventiloquinone L, the monomeric unit of cardinalin 3 has been described. The synthesis is completed in 7 steps with 10.5% and 13% overall yields for (-)-1-epi-ventiloquinone L and (+)-ventiloquinone L respectively. The key steps involve Dotz benzannulation of carbene 5 with alkyne 6 to give a substituted naphthalene moiety and oxa-Pictet-Spengler reaction to install the 1,3-dimethylpyran moiety

A concise and improved synthesis of (+)-eleutherin, (+)-allo-eleutherin and a formal synthesis of (+)-nocardione B

A concise and improved stereoselective synthesis of (+)-eleutherin, (+)-allo-eleutherin and the formal synthesis of (+)-nocardione B is described. The synthesis is based on a Dotz benzannulation and an improved oxa-Pictet-Spengler cyclization as the key steps. The synthesis is achieved in six steps in overall yields of 18% for eleutherin and 20% for allo-eleutherin. (C) 2011 Elsevier Ltd. All rights reserved

Synthesis of beta,gamma-disubstituted-gamma-lactones through a Johnson-Claisen rearrangement: a short route to xylobovide, nor-canadensolide, canadensolide, sporothriolide and santolinolide

The Johnson-Claisen rearrangement of allyl alcohols with chiral vicinal diol functionality was employed to access chiral beta,gamma-disubstituted-gamma-lactones in high enantio- and diastereoselectivity. These were efficiently converted into nor-canadensolide, the advanced gamma-(lactone-lactol) intermediate for xylobovide, canadensolide and sporothriolide and the lactone moiety of the santolinolides. (C) 200

A short enantioselective synthesis of (+)-eleutherin, (+)-allo-eleutherin and a formal synthesis of (+)-nocardione B

A short enantioselective synthesis of (+)-eleutherin, (+)-allo-eleutherin and the formal synthesis of (+)-nocardione B is described. The synthesis is completed in six steps in overall yields of 8% for eleutherin and 14% for allo-eleutherin. The synthetic strategy features ail efficient combination of the Dotz annulation reaction with a chiral alkyne and an oxa-Pictet Spengler reaction as the keys steps in the stereodivergent synthesis of (+)-eleutherin and (+)-allo-eleutherin. The synthesis of (S)-(+)-2-(2'-hydroxypropyl)-5-methoxy-1,4-naphthoquinone entails the formal synthesis of (+)-nocardione B. (c) 200

A Chiron Approach to the Total Synthesis of (-)-Juglomycin A, (+)-Kalafungin, (+)-Frenolicin B, and (+)-Deoxyfrenolicin

A general, efficient, and common strategy for the synthesis of (-)-juglomycin A, (+)-kalafungin, (+)-frenolicin B, and (+)-deoxyfrenolicin is reported here. The strategy involves the synthesis of a key building block alkyne from a cheap chiral pool material, D-glucono-delta-lactone, Dotz benzannulation, oxa-Pictet-Spengler reaction, and H2SO4-mediated epimerization