Diethylaluminum 2,2,6,6-tetramethylpiperidide

Among other reagents that effect epoxide ring opening are diethylaluminum 2,2,6,6-tetramethylpiperidide and magnesium (V-cyclohexyl-A-O -propy amide. 

Nozaki and Yamamoto reported a novel method for regiospecific isomerization of epoxides to allylic alcohols based on diethylaluminum 2,2,6,6-tetramethylpiperidide (DATMP) which can be prepared in situ from Et2AlCl and lithium 2,2,6,6-tetramethylpiperidide (LiTMP) (molar ratio 1 1) in benzene at 0 °C for 30 min [119], Reaction of DATMP (4 equiv.) with ( )-cyclododecene oxide in benzene at 0 °C for 3 h produced ( )-2-cyclododecen-l-ol in 90 % yield. Interestingly, the reaction of diepoxide 121, a useful synthetic intermediate in the preparation of Cig-Cecropia juvenile hormone, with DATMP furnished the triol 122 in 41 % yield (Sch. 83). 

Aluminum enolates can be obtained also by transmetallation of lithium enolates (Scheme 31 ). 3 Diethylaluminum enolates can be produced regiospecifically through reaction of diethylaluminum chloride and zinc dust with a-bromo ketones and esters (Scheme 32). Obviously zinc is involved in this reaction, but the mild conditions are in sharp contrast to the Refoimatsky reaction and support the existence of an aluminum enolate in this process. The same type of enolate can be obtained from r-butyi acetates and diethylaluminum 2,2,6,6-tetramethylpiperidide (DATMP), which is generated in situ from diethylaluminum chloride and LITMP (Scheme 33). ... 

A similar method for the formation of enolates derived from esters and ketones uses diethylaluminum 2,2,6,6-tetramethylpiperidide (DATMP), as shown in Scheme 58. ... 

ALLYLIC ALCOHOLS Benzeneselenol. 9-Borabicyclo[3.3.11 nonane. n-Butyllithium. Cuprous iodide-Grignard reagents. Diethylaluminum 2,2,6,6-tetramethylpiperidide. Fluorodimethoxyborane. rrans-l-Tri-n-butylstannyl-propene-3-tetrahydropyranyl ether. 

DIENES Diethylaluminum 2,2,6,6-tetramethylpiperidide. Lithium aluminum hydride. Lithium diphenylphosphide. Methylcopper. 

Tanaka et al. 231) prepared (518a) from allylic alcohol (514) via the epoxy silyl ether (515), which was ring opened with diethylaluminum 2,2,6,6-tetramethylpiperidide to afford the 3-ene-l,2-diol (516) Scheme 90). 

Vinyl epoxides can also be ring-opened via an Sn2 sense, as exemplified in the macrocyclization of the epoxy-tethered cyclopentenone 76, which was induced to occur by treatment with lithium 2,2,6,6-tetramethylpiperidide (LTMP) followed by the mild Lewis acid diethylaluminum chloride in THF. The enolate attacked exclusively from the a-position of the... 

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