The design of efficient and selective routes to a key 1,4-cis-substituted cyclohexylamide intermediate

This Letter describes the synthetic challenges in synthesising key 1,4-cis-substituted cyclohexylamide intermediate 1 for our research programme. Five different routes address the major issues of selectivity to afford the cis product in isomerically pure form and in high yield. Major purification issues were also encountered upon scaling some of the routes. The merits of the diverse routes are assessed and the reasoning given for which one was ultimately used for large-scale synthesis of 1.