Smoking compositions containing a flavorant-release additive
申请人:Philip Morris Incorporated
公开号:US04690157A1
公开(公告)日:1987-09-01
This invention provides smoking compositions which contain a novel hydroxylactone flavorant-release additive. Under cigarette smoking conditions, an additive such as 2-(1-hydroxy-1-phenylmethyl)-.gamma.-butyrolactone pyrolyzes into volatile benzaldehyde and .gamma.-butyrolactone constituents which enhance the flavor and aroma of the cigarette smoke.
Stereocontrolled aldol reactions of butyrolactone: erythro- selectivity via high coordination zinc complexes
作者:D.A. Widdowson、G.H. Wiebecke、D.J. Williams
DOI:10.1016/s0040-4039(00)88726-2
日期:1982.1
The stereoselection of the lithium catalysed aldol reaction of benzaldehyde and γ-butyrolactone is reversed by zinc ions. The intermediacy of octahedral or square pyramidal zinc complexes is invoked to explain these observations.
Nucleophilic Acyl Substitutions of Anhydrides with Protic Nucleophiles Catalyzed by Amphoteric, Oxomolybdenum Species
作者:Chien-Tien Chen、Jen-Huang Kuo、Vijay D. Pawar、Yogesh S. Munot、Shieu-Shien Weng、Cheng-Hsiu Ku、Cheng-Yuan Liu
DOI:10.1021/jo048363v
日期:2005.2.1
[GRAPHICS]Among six different group VIb oxometallic species examined, dioxomolybdenum dichloride and oxomolybdenum tetrachloride were the most efficient catalysts to facilitate nucleophilic acyl substitution (NAS) of anhydrides with a myriad array of alcohols, amines, and thiols in high yields and high chemoselectivity. In contrast to the well-recognized redox chemical behaviors associated with oxomolybdenum(VI) species, the catalytic NAS was unprecedented and tolerates virtually all kinds of functional groups. By using benzoic anhydride as a mediator for in situ generation of an incipient mixed anhydride -MoO2Cl2 adduct with a given functional alkanoic acid, one can achieve oleate, dipeptide, diphenylmethyl, N-Fmoc-alpha-amino, pyruvic, and tert-butylthio ester, N-tert-butylamide, and trityl methacrylate syntheses with appropriate protic nucleophiles. The amphoteric character of the Mo=O unit in oxomolybdenum chlorides was found to be responsible for the catalytic NAS profile as supported by a control NAS reaction of using an authentic adduct-MoOCl2(O-2-CBut)(2) between pivalic anhydride and MoO2Cl2 as the catalyst.
Catalytic Nucleophilic Acyl Substitution of Anhydrides by Amphoteric Vanadyl Triflate
[GRAPHICS]Among four vanadyl species examined, vanadyl triflate was the most efficient catalyst to facilitate nucleophilic acyl substitution of anhydrides with a myriad array of alcohols, amines, and thiols in high yields and high chemoselectivity. By using mixed-anhydride technique, one can achieve oleate and peptide syntheses. In marked contrast to common metal triflates, the amphoteric character of the V=O unit in vanadyl species was proven to be responsible for the catalytic profile in this process.
A cobalt-phosphine complex as mediator in the formation of carbon-carbon bonds
作者:Fulvia Orsini、Francesca Pelizzoni、Maurizio Pulici、Lidia M. Vallarino