The diastereoselectivity of the addition of enolateanions of ketones or esters to N-Methoxycarbonylimines generated in situ from α-Methoxy carbamates was studied.
One step synthesis of α-aminoalkylfurans was achieved by the reaction of α-methoxyurethanes or α-methoxyamides with furan. This method was applied to an efficient synthesis of pyridoxine.
The reaction of N-acyl-alpha-methoxyamines with allyl-, propargyl-, and benzylzinc bromides and Reformatsky reagents proceeds in THF at room temperature. Homoallyl- and homopropargylamines and beta-amino esters are synthesized in good yields.
Stereoselective synthesis of (±)-conhydrine, (±)-ephedrine, and (±)-N-methylephedrine
Crystal morphology of sucrose influenced by rotation axes parallel to growth planes
作者:Buguo Wang、C. Silber、H. Follner
DOI:10.1007/bf02898889
日期:2000.8
Three different types of growth forms of sucrose (P2(1)) were found by calculating with the Fourier transform method of crystal morphology. The observed central distances of the (100) and (001) faces are smaller than those calculated. It will be shown that the two-fold screw axis, which runs parallel to these faces, influences the rate of growth. The effectiveness of these symmetry elements is relative to the rotation angle around the face normal.