Yonggang Chen

An efficient stereocontrolled synthesis of (−)-10-epi-5β,11-dihydroxyeudesmane and (−)-4,10-epi-5β,11-dihydroxyeudesmane

Abstract A concise and efficient synthesis of (−)-10-epi-5β,11-dihydroxyeudesmane 1 and (−)-4,10-epi-5β,11-dihydroxyeudesmane 2, via (−)-10-epi-γ-eudesmol 5, was accomplished starting from (+)-dihydrocarvone. The salient feature of our synthesis is the utilization of substrate-directable epoxidation and homogeneous hydrogenation to control the stereochemistry at the C-4 and C-5 positions of the title compounds.

Total synthesis and stereochemistry of 13-hydroxy-α-eudesmol

Abstract The first total synthesis of both C-11 epimers of 13-hydroxy-α-eudesmol 1a and 1b by the use, as a key reaction, of the Sharpless asymmetric dihydroxylation of alkene 7 is presented. The absolute configuration of natural 13-hydroxy-α-eudesmol is established through comparison of the 1 H NMR spectrum of natural diol and synthetic diols. In our synthesis another natural product (+)-α-selinene 2 has also been accomplished.

First Synthesis of (+)-5α-Hydroxy-β-selinene and (–)-5β-Hydroxy-β-selinene

A facile and efficient synthesis of (+)-5α-hydroxy-β-selinene 1 and (–)-5β-hydroxy-β-selinene 2 starting from (+)-dihydrocarvone has been carried out.

A Facile Synthesis of 3-Oxo-7αH-eudesma-4-en-9β,12-diol

Abstract A facile synthesis of a mixture of the C-11 isomeric 3-oxo-7αH-eudesma-4-en-9β, 12-diol has been achieved from oxycarvone. The C-11 configuration of natural product is established through comparison of 1H NMR spectra between synthetic 1b, or the mixture of 1a and 1b, and natural diol.

THE ENANTIOSELECTIVE SYNTHESIS OF (+)-SELINA-3, 11-DIEN-9-OL

Abstract The title compound 1 was enantioselectively synthesized from oxycarvone in nine steps with an overall yield of 15%. The key step involves the p-toluenesulfonhydrazide assisted diastereoselective reductive rearrangement of allylic alcohol.

Total Synthesis of (–)-Baimuxifuranic Acid†

The first total synthesis of (–)-baimuxifuranic acid (1) starting from (–)-carvone is described: in our studies a surprising allylic oxidation was found in the oxidation of an α,β-unsaturated aldehyde 5 with silver oxide.

Facile Synthesis of 6β-Hydroxy-(7αH)-eudesm-4-en-3-one and β-Cyperone

A stereoselective total synthesis of 6β-hydroxy-(7αH)-eudesm-4-en-3-one 1 and β-cyperone 12 starting from (+)-dihydrocarvone 7 is described.