Corey method

An improtant modification of the Corey method was reported by Gerlach and Thalmann [17], who used silver ions (AgC104 or AgBF ) to activate the... 

Two superior, alternative reagents for the Corey method are the disulfides 23 and 24 [19], For example, in the first synthesis [20] of erythronolide B (27), the aglycone of the important antibiotic erythromycin B, cyclization of the hydroxy acid 25 to the 14-membered lactone 26 was effected in 50% yield via the thiol ester of 4-r-butyl-iV-isopropyl-2-mercaptoimidazole by heating in dry toluene under reflux (Scheme 9). 

Tritium-labelled disenedoylretronedne (64) required for studies of the biological properties of pyrrolizidine alkaloids, has been prepared by acylation of [9- H2]retronedne by senedoyl chloride. The label was introduced into retronedne following the Corey method of oxidation of the primary allylic alcohol function of unlabelled retronedne (65) with manganese dioxide in the presence of potassium... 

Chiral epoxides frequently play a key role as intermediates in organic synthesis and the development of methods for the catalytic asymmetric synthesis of such compounds therefore remains an area of intensive research. Methods have focused principally on the asymmetric electrophilic oxidation of alkenes and good enantioselectivity has been achieved [1]. An alternative to oxidative processes for the synthesis of epoxides is the reaction of sulfur ylides with aldehydes and ketones [2,3,4,5,6]. Sulfur ylide epoxidation is a carbon-carbon bond forming reaction and is complementary to oxidative methods. The standard conditions for this reaction utilize the original Corey method treatment of a sulfonium salt with a strong base in the presence of or followed by the addition of an aldehyde... 

Inubushi and cowoiicers have studied a similar unsymmetrical dialdehyde in the context of their fawcettimine synthesis." Dialdehyde (34) cyclizes under various conditions to give a mixture of enals (35 and 36 equation 100). Unexpectedly, both the Woodward and Corey methods give the same major product, providing (35) (36) ratios of 21 1 (80% yield) and 19 1 (62% yield), respectively. The opposite regioselectivity is obtained by using morpholine and camphoric acid in ether-HMPA solvent under these conditions, the (3S) (36) ratio is 1 25 and the yield is 54%. 

The Corey method for preparation of different fused 3-lactam systems [12,... 

Cyanohydrin-oxidation-substitution sequence (Corey method) [1] ... 

With the exception of the Corey method, all transformations are isohypsic. The Corey method involves hydrogen cyanide (HCN) as a sacrificial reagent to produce the intermediate cyanohydrin that is then oxidized to a cyanoketone and finally the cyano group is substituted by a methoxy group. The Fischer esterification and carbonylation methods do not involve sacrificial reagents. The former... 

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