Lactam & amide acetals XXI. Use of pyroglutamic acid and proline in chiral synthesis of conformationally constrained piperazinones
作者:Sanjay Jain、K Sujatha、K.V.Rama Krishna、Raja Roy、Jujhar Singh、Nitya Anand
DOI:10.1016/s0040-4020(01)81592-1
日期:1992.6
Making use of amide activation chiral synthesis of (+)-(1S,5R)- and (−)-(1R,5S)-3,8-diazabicyclo[3.2.1]octan-2-ones ( and ) has been achieved from L- and D-pyroglutamates, and of (−)-(2R,6S)-, (−)-(2S,6S)-, (+)-(2s,6R)- and (+)-(2R,6R)-2-methyl-1,4-diazabicyclo[4.3.0]nonan-5-ones (a,b,a and b) from L & D-proline methyl esters respectively. The key step of the synthesis involves a stereo-selective catalytic
利用酰胺活化手性合成了(+)-(1S,5R)-和(-)-(1R,5S)-3,8-二氮杂双环[3.2.1] octan-2-one(和) (-)-(2R,6S)-,(-)-(2S,6S)-,(+)-(2s,6R)-和(+)-(2R)分别来自L&D-脯氨酸甲酯的6R)-2-甲基-1,4-二氮杂双环[4.3.0]壬南-5-酮(a,b,a和b)。合成的关键步骤涉及立体选择性催化氢化,伴随着环化自发,邻的nitroenamines ,,和。尽管此反应在焦磷酸酯衍生的亚硝胺(和)的情况下是立体定向的,而在N-乙酰基脯氨酸衍生的亚硝胺(和)获得2R和2S非对映异构体,其中40%的非对映异构体带有2-CH定向的顺式至6-H。的哌嗪酮和上在室温下用HCl的甲醇溶液处理得到相应的旋光纯的5- aminomethylprolines和分别。