68697-44-9Relevant academic research and scientific papers
1,2-Halohydrincarboxylic acid esters and a process for their preparation
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, (2008/06/13)
1,2-Halohydrincarboxylic acid esters of the formula STR1 wherein R1, R2, R3, and R4 are identical or different and represent hydrogen, cyano and optionally substituted alkyl, alkenyl, aralkyl, aryl, alkoxycarbonyl, acyloxy, alkoxy and aryloxy, and furthermore R1 and R2 and/or R3 and R4, or R1 and R3 and/or R2 and R4 can be linked, forming a ring with the carbon atoms to which they are bonded; R5 represents hydrogen and optionally substituted alkyl, alkenyl, aralkyl, aryl, alkoxy and alkoxycarbonyl and X represents fluorine, chlorine, bromine and iodine; a process for preparing such 1,2-halohydrincarboxylic acid esters by reacting a cyclobutane-cis-1,2-diol of the formula STR2 with an orthoester of the formula STR3 wherein R1 -R5 have the previously ascribed significance and R6 -R8 are identical or different and represent optionally substituted alkyl, alkenyl, aralkyl and aryl, (or a ketene-acetal corresponding thereto) to give a 1,3-dioxolane and reacting the resultant 1,3-dioxolane with a halogenosilane or an acid halide. Also disclosed is a process for preparing compounds of the formula STR4 by contacting a 1,2-halohydrin ester of the formula given above with a base suitably at a temperature of 20° to 150° C.
The Diastereomeric 2-Aminocyclobutanols
Hartmann, Willy,Scholz, Karl-Heinz,Heine, Hans-Georg
, p. 1884 - 1889 (2007/10/02)
Syntheses of the previously unknown 2-aminocyclobutanols are described.The cis-isomer (5) is obtained in two steps by photosensitized cycloaddition of 4-oxazolin-2-one (1) or its acetyl derivative 2 to ethylene and subsequent alkaline hydrolysis of the adducts.Synthesis of the trans-isomer (6) is achieved by catalytic hydrogenation of trans-2-azidocyclobutanol (19), which is available in two steps from the cyclic orthobenzoate 12 and -acetate 13, resp., of cis-1,2-cyclobutandiol (11).
