Fragmentations and rearrangements of 22-hydroxyl substituted milbemycins - synthesis of a key lactone intermediate
作者:Geoffrey H. Baker、Roderick J.J. Dorgan、Nigel Hussain、Graham S. Macaulay、David O. Morgan
DOI:10.1016/0040-4039(94)85224-3
日期:1994.4
Beckmann fragmentation of 22-oximino milbemycins resulted in the cleavage of the C21–C22 bond to produce a key lactone intermediate which can be used to synthesise new spiroacetals. Cleavage of the C21–O25 bond and recyclisation to produce a furyl derivative is also described.
Alkoxy radicals in organic synthesis. A novel approach to a key intermediate in milbemycin chemistry
作者:Nigel Hussain、David O. Morgan、Charles R. White、John A. Murphy
DOI:10.1016/s0040-4039(00)73322-3
日期:1994.7
The fragmentation of nitrate ester (2) via an alkoxy radical to lactone (3) is described. This lactone is a key intermediate in the synthesis of semisynthetic milbemycins.