Xuechuan Hong

Benzothiazines in synthesis. Formal syntheses of (+)-curcumene and (+)-curcuphenol

A benzothiazine readily available in enantiomerically pure form via a stereoselective, intramolecular Michael addition reaction could be converted to a precursor to (+)-curcuphenol and to (+)-curcumene.

Benzothiazines in Synthesis : Studies Directed toward the Synthesis of Erogorgiaene

The use of benzothiazenes for the formal total synthesis of erogorgiaene and stereoselective total syntheses of two diastereomers of this natural product is described. In particular, the stereochemical course of a radical cyclization anticipated to give the correct relative stereochemistry for the synthesis of erogorgiaene is discussed utilizing both experimental and computational data.

Chapter 1 Recent progress in the chemistry of 2,1-benzothiazines

Publisher Summary This chapter discusses the progress of synthetic procedures and applications of 2,1-benzothiazines and related compounds. Togos group reported the preparation of the 2,1-benzothiazines via an ionic pathway with hypervalent iodine compounds. Using this method, it was found to be far easier to synthesize five- or seven-membered benzosultams and avoid the difficult deprotection of the N-alkyl group in the six-membered benzosultams to give the free NH group. The reaction of N-methoxy 2-(aryl)ethanesulfonamides with various hypervalent iodine reagents produced the cyclization products in various yields that were dependent on the dielectric constant of solvents. A reductive, intramolecular, free radical arylation using tributyltin hydride/AIBN was introduced by the Motherwell group. Cyclic sulfilimines are considered useful reagents in organic synthesis. The chemistry of cyclic sulfilimines has been studied extensively since the 1970s.