The synthesis of insect sex phermones

Conversion of Propargyl Alcohols to Chloroallenes and Arylalkynes Using the TiCl4/R3N Reagent System

Whereas the reaction of certain propargyl alcohols with TiCl4 in the presence of tertiary alkylamines gives the corresponding chloroallenes in 37-58% yields, reaction with the tertiary arylamines gives the corresponding arylalkynes in 68-77% yields.

Photoinduced Metalation of Nonactivated C−Cl Bonds with Samarium Diiodide: Synthesis of Alkenes with High (Z)-Selectivity through β-Elimination Reactions

[reaction: see text] The photoinduced metalation of nonactivated C-Cl bonds of O-acetyl chlorohydrins is promoted by samarium diiodide. As a result of this, beta-elimination of O-acetyl chlorohydrins is achieved, affording the corresponding (Z)-alkenes with total or high stereoselectivity.

A New Method for the Preparation of 1,5-Diynes. Synthesis of (4E,6Z,10Z)-4,6,10-Hexadecatrien-1-ol, the Pheromone Component of the Cocoa Pod Borer Moth Conopomorpha cramerella

[reaction: see text] A new method for the synthesis of 1,5-diynes, from the reaction of 1,3-dilithiopropyne and propargyl chlorides, was developed. This new methodology was used to prepare (4E,6Z,10Z)-4,6,10-hexadecatrien-1-ol, one of the pheromone components of the cocoa pod borer moth Conopomorpha cramerella, in 51% overall yield.

Formation of P-Ylide under Neutral and Metal-Free Conditions: Transformation of Aziridines and Epoxides to Conjugated Dienes In the Presence of Phosphine

A general approach to formation of the P-ylide from the reaction of aziridines or epoxides with organophosphine under neutral and metal-free conditions is realized. Conjugated diene derivatives based on this kind of P-ylide were prepared in a facile and convenient way.

Highly selective methodology for the direct conversion of aromatic aldehydes to glycol monoesters

Al(2)O(3)/MeSO(3)H (AMA) was found to be an extremely efficient reagent for the conversion of aromatic aldehydes and diols to glycol monoesters. The remarkable selectivity achieved with this reagent is an attractive feature of the present method.

Peroxovanadium-catalyzed oxidative esterification of aldehydes

The peroxovanadium species generated from V(2)O(5) and hydrogen peroxide, which is liberated from peroxy salts such as sodium perborate (SPB) or sodium percarbonate (SPC), transform aldehydes directly into esters in an alcoholic medium. Monoesters of diols have been achieved directly in one pot from aldehydes. High catalytic turnover number combined with inexpensive, easily available reagents and innocuous side products from the reaction make it a suitable alternative for the synthesis of esters from aldehydes.

A novel access to disubstituted acetylenes

Reactions of organometallic reagents with 1-(substituted ethynyl)-1H-1,2,3-benzotriazoles 5 derived from a variety of benzotriazolylmethyl ketones 3 afforded disubstituted acetylenes in synthetically useful yields.

A method for the identification of the double-bond position of isomeric linear tetradecenols and related compounds based on mass spectra of dimethyl disulfide derivatives

A simple method is presented for calculation of the double-bond position in linear tetradecenols based on mass spectral data of dimethyl disulfide derivatives. In this approach, the m/z ratios of the molecular ion and of one (or both) of the two most abundant fragment ions were utilized to calculate the double-bond position, without the requirement to identify both fragment ions resulting from carbon-carbon cleavage across what was originally the double bond. The approach was tested with mass spectra of dimethyl disulfide derivatives of 12 isomeric tetradecenols, and the double-bond position in each isomer was successfully identified by this method. The method was shown to work also for the corresponding acetates.