Enantiocontrolled Synthesis of (−)-9-<i>epi</i>-Pentazocine and (−)-Aphanorphine

We have developed novel asymmetric routes to (−)-9-epi-pentazocine and (−)-aphanorphine from a d-tyrosine derivative. The tricyclic frameworks of (−)-9-epi-pentazocine and (−)-aphanorphine were assembled stereoselectively via intramolecular Friedel−Crafts reaction of the corresponding bicyclic precursors, generated with titanium-promoted enyne cyclization and indium-initiated atom-transfer radical cyclization, respectively

Total Synthesis of (−)-5,6-Dihydrocineromycin B

An asymmetric total synthesis of (−)-5,6-dihydrocineromycin B has been accomplished in 13 steps from (−)-linalool O-triethylsilyl ether or 12 steps from geraniol. The present synthesis features (i) an intermolecular Wittig reaction involving an aldehyde possessing a ketophosphonate functionality and (ii) an intramolecular Horner−Wadsworth−Emmons olefination

Fast and Protecting-Group-Free Synthesis of (±)-Subincanadine C

The first total synthesis of (±)-subincanadine C has been accomplished in a protecting-group-free fashion. This pentacyclic indole alkaloid was synthesized in six steps from the known intermediate <b>4</b>, featuring Ni(COD)₂-mediated intramolecular Michael addition as a key transformation

Total Synthesis of (−)-5,6-Dihydrocineromycin B

An asymmetric total synthesis of (−)-5,6-dihydrocineromycin B has been accomplished in 13 steps from (−)-linalool O-triethylsilyl ether or 12 steps from geraniol. The present synthesis features (i) an intermolecular Wittig reaction involving an aldehyde possessing a ketophosphonate functionality and (ii) an intramolecular Horner−Wadsworth−Emmons olefination

Fast and Protecting-Group-Free Synthesis of (±)-Subincanadine C

The first total synthesis of (±)-subincanadine C has been accomplished in a protecting-group-free fashion. This pentacyclic indole alkaloid was synthesized in six steps from the known intermediate <b>4</b>, featuring Ni(COD)₂-mediated intramolecular Michael addition as a key transformation

Total Synthesis of (−)-5,6-Dihydrocineromycin B

An asymmetric total synthesis of (−)-5,6-dihydrocineromycin B has been accomplished in 13 steps from (−)-linalool O-triethylsilyl ether or 12 steps from geraniol. The present synthesis features (i) an intermolecular Wittig reaction involving an aldehyde possessing a ketophosphonate functionality and (ii) an intramolecular Horner−Wadsworth−Emmons olefination

Syntheses and Configuration Determination of (+)-Villatamines A and B, Two Marine Natural Products

The first total syntheses of (+)-villatamines A and B have been realized in six and five steps, respectively. The stereogenic center present in these two naturally occurring alkaloids should have an (S)-configuration based on our results

One-Step Construction of Tetrahydro-5<i>H</i>-indolo[3,2-<i>c</i>]quinolines from Benzyl Azides and Indoles via a Cascade Reaction Sequence

A novel one-step assembly of tetrahydro-5H-indolo[3,2-c]quinolines from benzyl azides and indoles via a formal [4 + 2] cycloaddition is described. A cascade reaction sequence, which involves benzyl azide-to-iminium rearrangement followed by two sequential Pictet–Spengler reactions, generates the tetracycles in moderate to excellent yields. The current method is applicable to a broad substrate scope and holds significant potential in constructing polycyclic indolines with tertiary and/or quaternary carbon centers

Expeditious Construction of (+)-Mintlactone via Intramolecular Hetero-Pauson−Khand Reaction

(+)-Mintlactone, a bicyclic monoterpene natural product, has been efficiently assembled from (−)-citronellol in three steps. The synthesis features nitrous acid-induced formal isopropylidene “demethanation” and the molybdenum-mediated intramolecular hetero-Pauson−Khand reaction

Novel Platinum-Catalyzed Tandem Reaction: An Efficient Approach to Construct Naphtho[1,2-<i>b</i>]furan

An efficient approach to synthesize naphtho[1,2-b]furan has been developed via platinum-catalyzed tandem reaction. This new tandem catalysis induces a cycloisomerization of allenyl ketone, followed by a 6π-electrocyclization-type reaction of carbene intermediate. The metal carbene proved to be an effective intermediate in the 6π-electrocyclization-type reaction