26343-65-7

Upstream product

• 82150-04-7 (3R,3aS)-3-Methyl-3,3a,4,5,6,7-hexahydro-benzo[c]isoxazole 
• 16111-99-2 6-Acetyl-1,4-dioxaspiro<4,5>decane 
• 2009-83-8 6-chloro-1-hexanol 
• 86542-29-2 1-nitro-6-octene 
• 86542-27-0 1-iodo-6-octene 
• 86542-25-8 1-chloro-6-octene 
• 52387-36-7 6-chlorohexanal 
• 874-23-7 2-acetylcyclohexanone 

Relevant academic research and scientific papers

A solution to the cyclic aldol problem

(equation presented) A protocol for achieving stereoselective aldol reactions with cyclic ketones is presented. In terms of yield, the process is particularly effective when a quaternary center at the α-carbon of the β-hydroxy ketone product is created. The stereochemical outcome, anti or syn, is achieved by the Lewis acid-mediated ring expansion of stereochemically homogeneous epoxides in a reaction related to the pinacol rearrangement.

Syntheses and Theoretical Studies of Exocyclic γ-Oxoalkenyltrimethylsilanes. An Approach to the Stereodefined Exocyclic Tetrasubstituted Alkenes

The Z-selectivity in the dehydration of α-hydroxy-γ-oxoalkyltrimethylsilanes under acidic conditions was studied from experimental and theoretical points of view.Experimental results showed that (Z)-γ-oxoalkenyltrimethylsilanes were thermodynamic products under these conditions.The dehydration studies of the compound involving the tert-butyl group instead of the TMS group pointed out that not only steric but also electronic effects of Si could contribute to the distribution of the products as well as their stereochemistries.Theoretical studies using ab initio calculation at the 6-31D* level indicated that the (Z)-isomer was thermodynamically more stable than the corresponding (E)-isomer.Detail examinations of the optimized structures showed that the configuration of Si in the (Z)-isomer was slightly distorted from tetrahedral.Interpretation of the geometrical change of Si to rationalization of the thermodynamic preference was discussed from the viewpoint of possible coordination of the carbonyl oxygen to Si.Those (Z)-γ-oxoalkenyltrimethylsilanes would have potential to be the novel type of alkenylmetal compounds in organic synthesis as we demonstrated in the construction of stereodefined exocyclic tetrasubstituted alkene.

Novel Srereocontrolled Syntheses of Exocyclic γ-Oxovinyltrimethylsilanes. A Potential Route for Stereodefined Exocyclic Tetrasubstituted Alkenes

The course of the dehydration of α-hydroxy-γ-oxotrimethylsilanes is highly dependent on the conditions to produce stereoselectively (Z)- and (E)-γ-oxovinyltrimethylsilanes, which are potential precursors for preparation of stereodefined exocyclic tetrasub

REDUCTION OF DELTA 2-ISOXAZOLINES. PART 3: RANEY-NICKEL CATALYZED FORMATION OF beta -HYDROXY KETONES.

The importance of the beta -hydroxy ketone moiety has led to the development of a wide variety of aldol type methodologies for its construction. A conceptually new approach to these 'aldol adducts' is presented on the basis of left bracket 3 plus 2 right bracket dipolar cycloaddition of in situ generated nitrile oxides and olefins followed by reduction of the resulting DELTA **2-isoxazolines. This approach provides a nice complement of the aldol type reaction. Optimum conditions for the transformation of DELTA **2-isoxazolines to beta -hydroxy ketones use Raney-nickel catalyst, boric acid, 5/1 MeOH/H//2O, and hydrogen gas. Under these mild conditions, 3-methyl-5-n-butyl- DELTA **2-isoxazoline is transformed to 4-hydroxy-2-octanone in high yield. Thus 'directed aldol' type adducts are readily available by selection of the appropriate olefin and nitrile oxide precursor (usually the 1 degree nitro compound).