Scheme 5.
The synthesis of e6preQ1 (2a) and bn6preQ1 (2b) was performed in analogy to the route outlined in Scheme 4 with an overall yield of 23% and 34%, respectively. For details see the Supporting Information File 1.
The synthesis of e6preQ1 (2a) and bn6preQ1 (2b) was performed in analogy to the route outlined in Scheme 4 with an overall yield of 23% and 34%, respectively. For details see the Supporting Information File 1.