First Asymmetric Hetero Diels−Alder Reaction of 1-Sulfinyl Dienes with Nitroso Derivatives. A New Entry to the Synthesis of Optically Pure 1,4-Imino-<scp>l</scp>-ribitol Derivatives
作者:C. Arribas、M. Carmen Carreño、José L. García-Ruano、Justo F. Rodríguez、Mercedes Santos、M. Ascensión Sanz-Tejedor
DOI:10.1021/ol0063611
日期:2000.10.1
Diels-Alder (HDA) cycloaddition of chiral 1-p-tolylsulfinyl-1,3-pentadiene with benzyl nitrosoformate, under mild conditions, yields 2H-1,2-oxazine 3 with complete regioselectivity and pi-facial diastereoselectivity. Sequential osmylation and protection of the resulting glycol gives the oxazine 5 which is directly transformed into enantiomerically pure 1,4,5-trideoxy-1,4-imino-L-ribitol 8 by reduction under
在温和条件下,手性1-对甲苯亚磺酰基-1,3-戊二烯与亚硝基甲酸酯苄基的杂Diels-Alder(HDA)环加成反应生成2H-1,2-恶嗪3,具有完全的区域选择性和pi-非对映选择性。顺序的渗透和保护所得的二醇得到恶嗪5,其通过在Pd / C下还原直接转化为对映体纯的1,4,5-三苯氧基-1,4-亚氨基-L-核糖醇8。