One-pot synthesis of 4-substituted 4-alkoxy-1,4-dihydro-3,1-benzoxazine-2-thiones by the reaction of 2-isothiocyanatobenzoates with organolithiums
摘要:
An efficient one-pot procedure for the preparation of 4-substituted 4-alkoxy-1,4-dihydro-3,1-benzoxazine-2-thiones from 2-isothiocyanatobenzoates has been developed. Thus, 2-isothiocyanatobenzoates were reacted with organolithiums including lithium enolates of acetates and tertiary acetamides in THF at -78 degrees C to give the desired products in generally good yields. (C) 2011 Elsevier Ltd. All rights reserved.
Concise Synthesis of Dictyoquinazol A via a Dimerisation–Cyclocondensation Sequence
摘要:
A two-step total synthesis of the neuroprotective alkaloid, dictyoquinazol A, has been achieved. The brevity of this synthesis was enabled by exploiting the hidden symmetry of the target molecule. Several structural analogues were also prepared using a similar strategy. These results provide a platform for future structure-activity relationship studies in the quest for a novel treatment for stroke.