作者:Maria Chrzanowska、Agnieszka Dreas
DOI:10.1016/j.tetasy.2004.06.038
日期:2004.8
The asymmetric syntheses of (R)-(+)- and (S)-(−)-O-methylbharatamine were performed using the lateral metallation strategy, in which (R)- and (S)-phenylalaninol were applied as chiral auxiliaries. The addition reaction of chiral o-toluamide carbanion to 6,7-dimethoxy-3,4-dihydroisoquinoline proceeded with a simultaneous cyclization reaction, giving both enantiomers of 2,3-dimethoxy-8-oxoberbine in
(R)-(+)-和(S)-(-)- O-甲基巴拉特明的不对称合成是通过侧向金属化策略进行的,其中将(R)-和(S)-苯丙氨醇用作手性助剂。手性邻甲苯甲酰碳负离子向6,7-二甲氧基-3,4-二氢异喹啉的加成反应同时进行环化反应,得到2,3-二甲氧基-8-氧代心rb的两种对映体,收率高(76%)对映选择性(99%ee)。每种对映异构体的氢化铝锂还原导致(R)-(+)-和(S)-(-)- O-甲基巴拉塔明,而不会损失对映选择性。