A chemical reaction is catalyzed in an organic solvent using a water soluble N-heterocyclic carbene homogeneous catalyst to form a reaction mixture. An aqueous phase in the reaction mixture. A solvent in which the catalyst is insoluble is added to the reaction mixture, causing the catalyst to migrate to the aqueous phase to form a catalyst-laden aqueous phase. The catalyst is extracted from the catalyst-laden aqueous phase.

A chemical reaction is catalyzed in an organic solvent using a water soluble N-heterocyclic carbene homogeneous catalyst to form a reaction mixture. An aqueous phase in the reaction mixture. A solvent in which the catalyst is insoluble is added to the reaction mixture, causing the catalyst to migrate to the aqueous phase to form a catalyst-laden aqueous phase. The catalyst is extracted from the catalyst-laden aqueous phase.

Methods of synthesizing intermediates useful for the synthesis of halichondrin B analogs are described.

Methods of synthesizing intermediates useful for the synthesis of halichondrin B analogs are described.

A method for separating a homogeneous catalyst from a solution includes forming a host-guest compound between a first isomer of the catalyst and inclusion compound in the solution and isolating the host-guest compound from the solution. The catalyst may be released from the inclusion compound by converting the first isomer of the catalyst to a second isomer of the catalyst.

A method for separating a homogeneous catalyst from a solution includes forming a host-guest compound between a first isomer of the catalyst and inclusion compound in the solution and isolating the host-guest compound from the solution. The catalyst may be released from the inclusion compound by converting the first isomer of the catalyst to a second isomer of the catalyst.

The present application relate to a process for preparation of 4-Methylene tetrahydrofuran compound of formula II, which is useful as an intermediate for the preparation of halichondrin B analogues such as Eribulin.

The present application relate to a process for preparation of 4-Methylene tetrahydrofuran compound of formula II, which is useful as an intermediate for the preparation of halichondrin B analogues such as Eribulin.

The invention provides methods for the synthesis of a halichondrin macrolides or analogs thereof through a cyclization reaction strategy. The strategy of the present invention involves subjecting an intermediate to Prins reaction conditions to afford a macrolide. The invention also provides compounds useful as intermediates in the synthesis of a halichondrin macrolides or analogs thereof and methods for preparing the same.

This describes homogeneous catalysts that are recoverable from solution by being phase selective and through host-guest interactions. An example of a method includes separating a water soluble N-heterocyclic carbene homogeneous catalyst from a solution by: (a) forming a host-guest compound between the catalyst and an inclusion compound in the solution; and (b) isolating the host-guest compound from the solution.