Alcohols as Efficient Intermolecular Initiators for a Highly Stereoselective Polyene Cyclisation Cascade.

The use of benzylic and allylic alcohols in HFIP solvent together with Ti(O Pr) has been shown to trigger a highly stereoselective polyene cyclisation cascade. Three new carbon-carbon bonds are made during the process and complete stereocontrol of up to five new stereogenic centers is observed. The reaction is efficient, has high functional group tolerance and is atom-economic generating water as a stoichiometric by-product.

Desymmetrization of meso-bisphosphates using copper catalysis and alkylzirconocene nucleophiles.

The desymmetrization of meso-compounds is a useful synthetic method, as illustrated by numerous applications of this strategy in natural product synthesis. Cu-catalyzed allylic desymmetrizations enable the enantioselective formation of carbon-carbon bonds, but these transformations are limited in substrate scope and by the use of highly reactive premade organometallic reagents at cryogenic temperatures. Here we show that diverse meso-bisphosphates in combination with alkylzirconium nucleophiles undergo highly regio-, diastereo- and enantio-selective Cu-catalyzed desymmetrization reactions.

Recent applications in natural product synthesis of dihydrofuran and -pyran formation by ring-closing alkene metathesis.

In the past two decades, alkene metathesis has risen in prominence to become a significant synthetic strategy for alkene formation. Many total syntheses of natural products have used this transformation. We review the use, from 2003 to 2015, of ring-closing alkene metathesis (RCM) for the generation of dihydrofurans or -pyrans in natural product synthesis.